po171 code
12-19-13, 02:31 PM
#61
Driver School Candidate
Join Date: Jul 2010
Location: IL
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
P0171 Code issues 1999 Lexus RX300 AWD
I keep getting the p0171 code... I have changed out the MAF sensor and still no luck...Runs for about a day or so and the CEL comes back on with the same code...Any suggestions would be wonderful.
01-26-17, 12:12 PM
#62
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
3 weeks ago I bought 2000 Lexus Rx300 for $2000 and it had 158xxx miles on it. When I bought this lexus CEL was ON and my scanner showed me P0171 code. I have performed the following things on my RX300 and failed miserably :
1. Cleaned the MAF and erased the codes but after four miles CEL came back.
2. Replaced the MAF with new one and erased the codes but again CEL light came back after 4 miles.
3. Checked all the Vacuum lines and replaced few vacuum lines with new hose .... again no luck.
4. Tested the air intake manifold with break cleaner spray for any potential leak and found out there was no leak.
Last week I thought that I should check engine oil and coolant and I found out there was no coolant in the radiator. I had coolant at home so filled the radiator with coolant and started the car, after 1min I saw water coming from timing belt cover.
Long story short : Bought timing belt kit, 2 cam seal and 1 crank seal for $200 from amazon. My mechanic charged me $150 to install the new parts. Yesterday when I picked up my lexus CEL was on and on my way home from mechanic shop the CEL light turned off by itself.
I believe the air was getting in the engine through Cam seals or crank seal. However, my CEL light turned off and I will update you guys after 1000 miles.
1. Cleaned the MAF and erased the codes but after four miles CEL came back.
2. Replaced the MAF with new one and erased the codes but again CEL light came back after 4 miles.
3. Checked all the Vacuum lines and replaced few vacuum lines with new hose .... again no luck.
4. Tested the air intake manifold with break cleaner spray for any potential leak and found out there was no leak.
Last week I thought that I should check engine oil and coolant and I found out there was no coolant in the radiator. I had coolant at home so filled the radiator with coolant and started the car, after 1min I saw water coming from timing belt cover.
Long story short : Bought timing belt kit, 2 cam seal and 1 crank seal for $200 from amazon. My mechanic charged me $150 to install the new parts. Yesterday when I picked up my lexus CEL was on and on my way home from mechanic shop the CEL light turned off by itself.
I believe the air was getting in the engine through Cam seals or crank seal. However, my CEL light turned off and I will update you guys after 1000 miles.
01-26-17, 03:59 PM
#63
Moderator
3 weeks ago I bought 2000 Lexus Rx300 for $2000 and it had 158xxx miles on it. When I bought this lexus CEL was ON and my scanner showed me P0171 code. I have performed the following things on my RX300 and failed miserably :
1. Cleaned the MAF and erased the codes but after four miles CEL came back.
2. Replaced the MAF with new one and erased the codes but again CEL light came back after 4 miles.
3. Checked all the Vacuum lines and replaced few vacuum lines with new hose .... again no luck.
4. Tested the air intake manifold with break cleaner spray for any potential leak and found out there was no leak.
Last week I thought that I should check engine oil and coolant and I found out there was no coolant in the radiator. I had coolant at home so filled the radiator with coolant and started the car, after 1min I saw water coming from timing belt cover.
Long story short : Bought timing belt kit, 2 cam seal and 1 crank seal for $200 from amazon. My mechanic charged me $150 to install the new parts. Yesterday when I picked up my lexus CEL was on and on my way home from mechanic shop the CEL light turned off by itself.
I believe the air was getting in the engine through Cam seals or crank seal. However, my CEL light turned off and I will update you guys after 1000 miles.
1. Cleaned the MAF and erased the codes but after four miles CEL came back.
2. Replaced the MAF with new one and erased the codes but again CEL light came back after 4 miles.
3. Checked all the Vacuum lines and replaced few vacuum lines with new hose .... again no luck.
4. Tested the air intake manifold with break cleaner spray for any potential leak and found out there was no leak.
Last week I thought that I should check engine oil and coolant and I found out there was no coolant in the radiator. I had coolant at home so filled the radiator with coolant and started the car, after 1min I saw water coming from timing belt cover.
Long story short : Bought timing belt kit, 2 cam seal and 1 crank seal for $200 from amazon. My mechanic charged me $150 to install the new parts. Yesterday when I picked up my lexus CEL was on and on my way home from mechanic shop the CEL light turned off by itself.
I believe the air was getting in the engine through Cam seals or crank seal. However, my CEL light turned off and I will update you guys after 1000 miles.
Salim
01-26-17, 04:40 PM
#64
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
01-30-17, 06:17 PM
#65
$2000!!!! That's it!
Hell....I'll buy another one! I have yr 2000 have 287K
Seats are ripped to crap...well mine anyway..and have
misfires a lot..but it keeps going. Hell..for that money
screw buying another engine..but then for under a grand
I'm thinking of taking it. Just put new Control arms..rotors
all 4..new tires..Brakes. Getting ready to do the struts..KYBs
I mean what the hell.
Seats are ripped to crap...well mine anyway..and have
misfires a lot..but it keeps going. Hell..for that money
screw buying another engine..but then for under a grand
I'm thinking of taking it. Just put new Control arms..rotors
all 4..new tires..Brakes. Getting ready to do the struts..KYBs
I mean what the hell.
05-02-17, 04:35 AM
#66
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Update on P0171
Guys , I was finally able to takecare of p0171 code. I believe there were multiple issues with my Lexus when I start fixing it. The 1st one was the ideal valve which is on the left side of air manifold. I replaced that valve with used part bought it from eBay for $28. After replacing the air manifold ideal valve , I disconnect negative battery terminal so that I can reset the ecu on my lexus for 5mins, put it back and drove car for 40miles engine light came back.
Next day I went to advance auto n bought 15feet of vacuum hose for $15 and replaced all the vacuum hoses one by one , reset the light and guess what .... P0171 code is gone, however , after 35miles CEL came back now the code is P0440 which is most likely vapor canistor. Now I'm working on P0440 code and I will update u soon .
Next day I went to advance auto n bought 15feet of vacuum hose for $15 and replaced all the vacuum hoses one by one , reset the light and guess what .... P0171 code is gone, however , after 35miles CEL came back now the code is P0440 which is most likely vapor canistor. Now I'm working on P0440 code and I will update u soon .
11-24-17, 08:10 PM
#67
Driver School Candidate
Guys , I was finally able to takecare of p0171 code. I believe there were multiple issues with my Lexus when I start fixing it. The 1st one was the ideal valve which is on the left side of air manifold. I replaced that valve with used part bought it from eBay for $28. After replacing the air manifold ideal valve , I disconnect negative battery terminal so that I can reset the ecu on my lexus for 5mins, put it back and drove car for 40miles engine light came back.
Next day I went to advance auto n bought 15feet of vacuum hose for $15 and replaced all the vacuum hoses one by one , reset the light and guess what .... P0171 code is gone, however , after 35miles CEL came back now the code is P0440 which is most likely vapor canistor. Now I'm working on P0440 code and I will update u soon .
Next day I went to advance auto n bought 15feet of vacuum hose for $15 and replaced all the vacuum hoses one by one , reset the light and guess what .... P0171 code is gone, however , after 35miles CEL came back now the code is P0440 which is most likely vapor canistor. Now I'm working on P0440 code and I will update u soon .
11-25-17, 06:10 AM
#68
dindih,
get a bluetooth OBDII code reader and see what your fuel trims are on both banks at idle and 2000 rpm. A P0171 code means the fuel trim is higher than 25% at some condition on bank1 (the bank near the firewall). If trims are actually high on both banks (even though it didn't throw the corresponding P0174 code for bank2), it is likely caused by the MAF or some break/opening in the air path between the MAF and the engine. If the trims are high only at idle it is likely a vacuum leak. At all rpms, the MAF. If it is only one bank that is truly high trims, the same rules apply, but look specifically at that bank and also consider changing the A/F sensor (but only with a new Denso 234-9009 from a reputable seller).
It is a good idea for our old cars to check all vacuum lines for cracks as the tubing is no longer flexible due to age.
get a bluetooth OBDII code reader and see what your fuel trims are on both banks at idle and 2000 rpm. A P0171 code means the fuel trim is higher than 25% at some condition on bank1 (the bank near the firewall). If trims are actually high on both banks (even though it didn't throw the corresponding P0174 code for bank2), it is likely caused by the MAF or some break/opening in the air path between the MAF and the engine. If the trims are high only at idle it is likely a vacuum leak. At all rpms, the MAF. If it is only one bank that is truly high trims, the same rules apply, but look specifically at that bank and also consider changing the A/F sensor (but only with a new Denso 234-9009 from a reputable seller).
It is a good idea for our old cars to check all vacuum lines for cracks as the tubing is no longer flexible due to age.
11-26-17, 05:41 AM
#69
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
After changing all the vacuum hoses that code never came back .... however new code came up which was P0440 n I have changed the fuel cap with after market but code came back again .Please note that after market gas caps r not good because as soon as I replaced the after market gas cap with Toyota original gas cap light was gone .
Last month I checked my system with the scanner there is pending code p0446 I don’t know what is that . Light never turned on from last one month I’m not sure what’s going on with that.
12-06-17, 03:32 PM
#70
Driver School Candidate
I have a CEL with P0171 and it won't go away
I have a 2000 RX300 AWD at 145,000 miles. For about a month now I have the P0171 code (and nothing else). I have a Innova 3100j Diagnostic Code Reader that I use when I get a CEL. After trying a fix I clear the code using this scan tool.
So far I have tried:
1) Checked all the vacuum hoses for a loose connection, hole or a disconnected hose. Tightened the connections without replacing the hoses. P0171 came back.
2) Cleaned the MAF sensor (both the bulb and the two wires inside one of the pipes) using a CRC MAF cleaner then put it back. It took about 50-60 miles but the code P0171 came back.
3) Replaced the MAF with a brand new MAF (Denso OEM from a Toyota dealership). The code again came back.
4) Replaced the A/F ratio sensor Bank 1 Sensor 1 (underneath the car). This is a Denso 234-9009 sensor I bought from EBay. The old sensor looked very bad. But the code P0171 came back again.
5) I tried to duct tape the intake ducts at the hose clamps after the MAF (after tightening the clams with a screw driver) in case I was getting small air leaks. The code P0171 again came back.
One thing is for sure my car smells like running rich, especially at cold start, I am getting poor fuel economy, although my info screen says I am getting 16 mpg in city driving my manual calculations based on the fuel I put in and the miles I drive from full tank to full tank is lower than that (~13 mpg). I also see black carbon deposits at the tip of the exhaust pipe. It appears that the fuel system is sending more fuel than the required ratio, yet the car (sensors?) thinks it is lean. I am afraid I may ruin the catalytic converter.
I ordered a new A/F ratio sensor from the Toyota dealership this time (in case the one I bough from EBay about a month ago has some problems, perhaps was not made by Denso?) but I did not pick it up yet from the dealership. I will replace the new B1S1 A/F sensor again. Could the 3rd oxygen sensor after the Cat converter throw only P0171? My car is a 2000 RX300, do you actually get P0174 in the 2000 RX300 models?
Am I missing something here? Or is it time to go to a shop where they can look at the trim info to get a better insight?
For years I have enjoyed reading the posts and benefited from the wisdom and knowledge in this Forum from many folks like LexMex, Salim, and many others. Perhaps I can make a small contribution this time to actually give something back.
So far I have tried:
1) Checked all the vacuum hoses for a loose connection, hole or a disconnected hose. Tightened the connections without replacing the hoses. P0171 came back.
2) Cleaned the MAF sensor (both the bulb and the two wires inside one of the pipes) using a CRC MAF cleaner then put it back. It took about 50-60 miles but the code P0171 came back.
3) Replaced the MAF with a brand new MAF (Denso OEM from a Toyota dealership). The code again came back.
4) Replaced the A/F ratio sensor Bank 1 Sensor 1 (underneath the car). This is a Denso 234-9009 sensor I bought from EBay. The old sensor looked very bad. But the code P0171 came back again.
5) I tried to duct tape the intake ducts at the hose clamps after the MAF (after tightening the clams with a screw driver) in case I was getting small air leaks. The code P0171 again came back.
One thing is for sure my car smells like running rich, especially at cold start, I am getting poor fuel economy, although my info screen says I am getting 16 mpg in city driving my manual calculations based on the fuel I put in and the miles I drive from full tank to full tank is lower than that (~13 mpg). I also see black carbon deposits at the tip of the exhaust pipe. It appears that the fuel system is sending more fuel than the required ratio, yet the car (sensors?) thinks it is lean. I am afraid I may ruin the catalytic converter.
I ordered a new A/F ratio sensor from the Toyota dealership this time (in case the one I bough from EBay about a month ago has some problems, perhaps was not made by Denso?) but I did not pick it up yet from the dealership. I will replace the new B1S1 A/F sensor again. Could the 3rd oxygen sensor after the Cat converter throw only P0171? My car is a 2000 RX300, do you actually get P0174 in the 2000 RX300 models?
Am I missing something here? Or is it time to go to a shop where they can look at the trim info to get a better insight?
For years I have enjoyed reading the posts and benefited from the wisdom and knowledge in this Forum from many folks like LexMex, Salim, and many others. Perhaps I can make a small contribution this time to actually give something back.
12-13-17, 04:47 AM
#71
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
I suggest u should change all the vacuum hoses , there is no way u can find a pin hole size leak in the vacuum lines. It will cost you $15 dollars and 1hour to change all vacuum lines ...
It will be a good idea to check the ideal valve too mine had leak .... use brake cleaner spray to find the leak on the ideal valve ... there is another thread on it which will show u how to check for leak.
Or
may be you have leak in the air manifold gasket.
Just to give u update on my lexus .... after changing gas cap .... all codes were cleared n I sold mine lexus 2 weeks ago and bought myself 2008 Lexus IS250.
It will be a good idea to check the ideal valve too mine had leak .... use brake cleaner spray to find the leak on the ideal valve ... there is another thread on it which will show u how to check for leak.
Or
may be you have leak in the air manifold gasket.
Just to give u update on my lexus .... after changing gas cap .... all codes were cleared n I sold mine lexus 2 weeks ago and bought myself 2008 Lexus IS250.
06-04-18, 06:59 PM
#72
Driver School Candidate
Join Date: Mar 2018
Location: Pennsylvania
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I suggest u should change all the vacuum hoses , there is no way u can find a pin hole size leak in the vacuum lines. It will cost you $15 dollars and 1hour to change all vacuum lines ...
It will be a good idea to check the ideal valve too mine had leak .... use brake cleaner spray to find the leak on the ideal valve ... there is another thread on it which will show u how to check for leak.
Or
may be you have leak in the air manifold gasket.
Just to give u update on my lexus .... after changing gas cap .... all codes were cleared n I sold mine lexus 2 weeks ago and bought myself 2008 Lexus IS250.
It will be a good idea to check the ideal valve too mine had leak .... use brake cleaner spray to find the leak on the ideal valve ... there is another thread on it which will show u how to check for leak.
Or
may be you have leak in the air manifold gasket.
Just to give u update on my lexus .... after changing gas cap .... all codes were cleared n I sold mine lexus 2 weeks ago and bought myself 2008 Lexus IS250.
I have a 2000 RX300 AWD at 145,000 miles. For about a month now I have the P0171 code (and nothing else). I have a Innova 3100j Diagnostic Code Reader that I use when I get a CEL. After trying a fix I clear the code using this scan tool.
So far I have tried:
1) Checked all the vacuum hoses for a loose connection, hole or a disconnected hose. Tightened the connections without replacing the hoses. P0171 came back.
2) Cleaned the MAF sensor (both the bulb and the two wires inside one of the pipes) using a CRC MAF cleaner then put it back. It took about 50-60 miles but the code P0171 came back.
3) Replaced the MAF with a brand new MAF (Denso OEM from a Toyota dealership). The code again came back.
4) Replaced the A/F ratio sensor Bank 1 Sensor 1 (underneath the car). This is a Denso 234-9009 sensor I bought from EBay. The old sensor looked very bad. But the code P0171 came back again.
5) I tried to duct tape the intake ducts at the hose clamps after the MAF (after tightening the clams with a screw driver) in case I was getting small air leaks. The code P0171 again came back.
One thing is for sure my car smells like running rich, especially at cold start, I am getting poor fuel economy, although my info screen says I am getting 16 mpg in city driving my manual calculations based on the fuel I put in and the miles I drive from full tank to full tank is lower than that (~13 mpg). I also see black carbon deposits at the tip of the exhaust pipe. It appears that the fuel system is sending more fuel than the required ratio, yet the car (sensors?) thinks it is lean. I am afraid I may ruin the catalytic converter.
I ordered a new A/F ratio sensor from the Toyota dealership this time (in case the one I bough from EBay about a month ago has some problems, perhaps was not made by Denso?) but I did not pick it up yet from the dealership. I will replace the new B1S1 A/F sensor again. Could the 3rd oxygen sensor after the Cat converter throw only P0171? My car is a 2000 RX300, do you actually get P0174 in the 2000 RX300 models?
Am I missing something here? Or is it time to go to a shop where they can look at the trim info to get a better insight?
For years I have enjoyed reading the posts and benefited from the wisdom and knowledge in this Forum from many folks like LexMex, Salim, and many others. Perhaps I can make a small contribution this time to actually give something back.
So far I have tried:
1) Checked all the vacuum hoses for a loose connection, hole or a disconnected hose. Tightened the connections without replacing the hoses. P0171 came back.
2) Cleaned the MAF sensor (both the bulb and the two wires inside one of the pipes) using a CRC MAF cleaner then put it back. It took about 50-60 miles but the code P0171 came back.
3) Replaced the MAF with a brand new MAF (Denso OEM from a Toyota dealership). The code again came back.
4) Replaced the A/F ratio sensor Bank 1 Sensor 1 (underneath the car). This is a Denso 234-9009 sensor I bought from EBay. The old sensor looked very bad. But the code P0171 came back again.
5) I tried to duct tape the intake ducts at the hose clamps after the MAF (after tightening the clams with a screw driver) in case I was getting small air leaks. The code P0171 again came back.
One thing is for sure my car smells like running rich, especially at cold start, I am getting poor fuel economy, although my info screen says I am getting 16 mpg in city driving my manual calculations based on the fuel I put in and the miles I drive from full tank to full tank is lower than that (~13 mpg). I also see black carbon deposits at the tip of the exhaust pipe. It appears that the fuel system is sending more fuel than the required ratio, yet the car (sensors?) thinks it is lean. I am afraid I may ruin the catalytic converter.
I ordered a new A/F ratio sensor from the Toyota dealership this time (in case the one I bough from EBay about a month ago has some problems, perhaps was not made by Denso?) but I did not pick it up yet from the dealership. I will replace the new B1S1 A/F sensor again. Could the 3rd oxygen sensor after the Cat converter throw only P0171? My car is a 2000 RX300, do you actually get P0174 in the 2000 RX300 models?
Am I missing something here? Or is it time to go to a shop where they can look at the trim info to get a better insight?
For years I have enjoyed reading the posts and benefited from the wisdom and knowledge in this Forum from many folks like LexMex, Salim, and many others. Perhaps I can make a small contribution this time to actually give something back.
06-05-18, 03:14 PM
#73
I am having the exact same issue with my 2000 RX. You’ve described my RX to the T so I’m hoping that you’ve found a solution and have an update. I’ve replaced every hose,all air fuel/O2 sensors, plugs, coils, MAF, all intake gaskets, evap hoses, all new catalytic converters, OCV’s and filters, injectors, fuel pump and filter, intake boots and air filter. All with the same result. P0171!! I have so much invested that I have no choice but to keep going since I’ll never be able to make any of it back by selling it like it is. It runs terrible and smells horrible anytime I have to sit in traffic. I’m going to try replacing the coolant temp sensor on the timing belt side even though the temp gauge always reads normal. I’m at my wits end with this and need all the help I can get. I’m a mechanic by trade and this thing is kicking my but so I’m determined to figure this out. Besides, it’s got nearly 200k on it and the body has its share of rust so it’s not worth taking it to a dealer. Thanks in advance for any help.
06-05-18, 08:04 PM
#74
Driver School Candidate
Join Date: Jan 2017
Location: ny
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
My P0171 code went away when I replaced the gas fuel cap with Toyota orginal gas cap .... if u still have problem try to change the valve which is on air manifold on the right side .
What r your low and high lean numbers ? Use scanner to read these number.
What r your low and high lean numbers ? Use scanner to read these number.
