When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am a new member to the Forum, but want to thank everyone for the great threads on here and helpful advice! I bought a used 2000 Lexus es300 PE with 250,000 miles on it for a great deal. This car is from the West coast and was well maintained. I am not a mechanic, but have done several repairs on other vehicles myself with a greater level of difficulty that most would have passed on. Anyway here is my issue.... Upon puchasing the car I had a random Solid Check Engine/Trac cel for about a couple weeks randomly popping up making the car idle rough and sending it into limp mode, I took it to the parts store, ran the scan tool and got a p1135 Air/Fuel sensor code B1 S1. I replaced the front sensor, cleared the code and this took care of it. I also replaced the battery a couple months later and had relatively no issues except for a fairly noticeable gas smell from the exhaust that has been there since buying the car. It ran pretty good so I left it alone. So about a year passed and I'm on my way home from work, solid check engine/Trac light comes on and the car goes into limp mode not letting it shift info 4 gear and disabling the OD. I go to the parts store again, scan the code, and get....
* P0330 (Confirmed) Knock Sensor 2 B2 code.
* C1201, C0226, C0236, C0246, C0256, C1223
*Most of these codes are a separate issue related to the ABS system!
I live in MN and it has been very hot the last two months with high humidity in the 80 to 90% range, which I considered could also be factoring into the random codes popping up. Anyway I call my mechanic buddy in Tucson, AZ to see if he thinks I can handle this knock sensor job myself and what parts I need to do the job. So I find out that a new knock sensor costs $160, that it's better to replace them both, the wiring harness, and get a new gasket set for the manifold. I managed to get all the parts for $406, but it would have been $450 without the 10% discount the guy gave me at the auto parts store! 🙀 So I start taking apart the car to do this repair . (I should have drained the coolant first! I highly recommend doing this, as I had a mess upon taking off hoses and the manifold!) This job was causing me to doubt myself and I was thinking am I in over my head? I proceeded anyway knowing the location of the sensors from this forum and or her resources. So after unhooking like 12 hoses, multiple bolts and wiring clips I get the top section of the manifold loose w/the carb assembly still attached to multiple hoses I lift it up and to the right side of the engine compartment and use bungee cords to hold it out of the way. (I have bolts everywhere, I should have kept everything organized and marked my hoses for reassembly but I did not. (I recommend doing this for everyone considering this repair.) light at the end of the tunnel. After removing the bottom section of the malifold and coolant going everywhere. I hang it along side the top portion of the manifold, it's also still connected to multiple hoses on the right side. I see the knock sensors and only one short hose along the top of them. (They also recommend changing this hose, but this one was still in good shape so decided to reuse it.) so i now have access to both knock sensors. I take them both out, and replace them with the new parts. I plug in the new wire harness to the back of both sensors and run the cords along the right side along the old harness leaving the old harness attached to the main clip for now. I vacuum out all the debris and coolant. I start to remove all the old gaskets and realize the water outlet to the left of the bottom manifold section will also have to be removed to get the last gasket off. PITA and two long bolts of the like 6 in this part are extremely tight and hard to get out.( I recommend a breaker bar here to get these two bolts loose) So after removing the water pump and cleaning up the dirty parts for new gaskets I start to reassemble everything. I bolt it all back down. (Recommend using a torque wrench to get the right FP for the bolts along the manifold to the gasket.) I did not do this because I'm old school and like making more problems for myself down the road! 😎 I get everything back together, add coolant because I lost so much during the repair and reconnect the negative lead to the battery. I start it up, little rough upon start up tell everything got flowing again, and no dash lights on. I proceed to drive a couple miles to make sure everything is safe. It seems ok, No check engine/Trac cel coming up. I shut the car off, cleaned up my mess from the repair and started it back up. Both Lights back up solid check engine/trac. since I did the repairs at another location about 23 miles away, I drove home with the lights on the dash instead of resetting it. Drove fine, shifted fine all the way home. I shut it down upon arrival, check under the hood at the coolant level, and the overflow was empty. I assumed this would happen because the amount I lost during the repair and the system restablishing itself. I removed the radiator cap, it took about a 1/4 quart, and then refilled the overflow tank to the full level. When I restarted the car to put it in the garage, it made a horrible continuous knocking noise from the motor, and sounded like a steel ball knocking around in the top of the manifold? The car became very sluggish, low idle and jerking in park, and upon acceleration? I put it in the garage and unplugged the negative lead to the battery. The next morning I came out reconnected the battery and again checked my work. I found I forgot a vacuum hose leading from the same bundle that lead to the intake,but not the intake vacuum hose, the small one that heads left under that small black round thing. I hook this back in, reset the computer again and had to take it to work. So upon restarting the car, the check engine light comes on flashing repeatedly and the engine knock was a bit less but uncomfortable. I had to drive into work this way, hesitating, jerking, check engine light flashing, then going back and forth to a solid light again. I drove it to auto parts store after work to rerun the codes....
* P1155, P1135, P0305, P0325
*P0305 Misfire on Cylinder 5
* P1155/P1135 - Upstream and Downstream
O2 Sensors
*P0325 - Random Misfires
So I swapped out the Front O2 Air/Fuel Sensor (B1 S1, The one a put in 7 months prior. The parts store let me return it and gave me a new one.) I wanted to rule this part out. I got six new NGK plugs and one new ignition coil for cylinder 5. I changed out all the plugs and one plug in Cylinder 5 had the gap pushed all the way into the ignitior of the plug? How does this happen??? All the coils looked pretty good just looking them over except Cylinder 5's looked oxidated and not as clean, so I swapped this one out with a new coil. I also cleaned out the MAF Sensor just in case, this was fairly dirty also. Still sluggish and sputtering at about 65MPH or just randomly and will not shift into 4th on the highway and running at about 4.5 on the Tach. Check Engine/Trac Lights still on the dash, and the only thing I can think of is to clean the throttle body and replace the Downstream O2 Sensor. I am scared to pull the codes again since I am already out like $500 on this one. I guess I have saved about $2500 in labor costs doing this myself, but I will pull the updated codes for this tomorrow and keep you all updated. Any help with this will be greatly appreciated. This has been a real job, and have about 10 hours of labor into this whole process. I must say I have learned a great deal about this car from the experience though. T
I am a new member to the Forum, but want to thank everyone for the great threads on here and helpful advice! I bought a used 2000 Lexus es300 PE with 250,000 miles on it for a great deal. This car is from the West coast and was well maintained. I am not a mechanic, but have done several repairs on other vehicles myself with a greater level of difficulty that most would have passed on. Anyway here is my issue.... Upon puchasing the car I had a random Solid Check Engine/Trac cel for about a couple weeks randomly popping up making the car idle rough and sending it into limp mode, I took it to the parts store, ran the scan tool and got a p1135 Air/Fuel sensor code B1 S1. I replaced the front sensor, cleared the code and this took care of it. I also replaced the battery a couple months later and had relatively no issues except for a fairly noticeable gas smell from the exhaust that has been there since buying the car. It ran pretty good so I left it alone. So about a year passed and I'm on my way home from work, solid check engine/Trac light comes on and the car goes into limp mode not letting it shift info 4 gear and disabling the OD. I go to the parts store again, scan the code, and get....
* P0330 (Confirmed) Knock Sensor 2 B2 code.
* C1201, C0226, C0236, C0246, C0256, C1223
*Most of these codes are a separate issue related to the ABS system!
I live in MN and it has been very hot the last two months with high humidity in the 80 to 90% range, which I considered could also be factoring into the random codes popping up. Anyway I call my mechanic buddy in Tucson, AZ to see if he thinks I can handle this knock sensor job myself and what parts I need to do the job. So I find out that a new knock sensor costs $160, that it's better to replace them both, the wiring harness, and get a new gasket set for the manifold. I managed to get all the parts for $406, but it would have been $450 without the 10% discount the guy gave me at the auto parts store! 🙀 So I start taking apart the car to do this repair . (I should have drained the coolant first! I highly recommend doing this, as I had a mess upon taking off hoses and the manifold!) This job was causing me to doubt myself and I was thinking am I in over my head? I proceeded anyway knowing the location of the sensors from this forum and or her resources. So after unhooking like 12 hoses, multiple bolts and wiring clips I get the top section of the manifold loose w/the carb assembly still attached to multiple hoses I lift it up and to the right side of the engine compartment and use bungee cords to hold it out of the way. (I have bolts everywhere, I should have kept everything organized and marked my hoses for reassembly but I did not. (I recommend doing this for everyone considering this repair.) light at the end of the tunnel. After removing the bottom section of the malifold and coolant going everywhere. I hang it along side the top portion of the manifold, it's also still connected to multiple hoses on the right side. I see the knock sensors and only one short hose along the top of them. (They also recommend changing this hose, but this one was still in good shape so decided to reuse it.) so i now have access to both knock sensors. I take them both out, and replace them with the new parts. I plug in the new wire harness to the back of both sensors and run the cords along the right side along the old harness leaving the old harness attached to the main clip for now. I vacuum out all the debris and coolant. I start to remove all the old gaskets and realize the water outlet to the left of the bottom manifold section will also have to be removed to get the last gasket off. PITA and two long bolts of the like 6 in this part are extremely tight and hard to get out.( I recommend a breaker bar here to get these two bolts loose) So after removing the water pump and cleaning up the dirty parts for new gaskets I start to reassemble everything. I bolt it all back down. (Recommend using a torque wrench to get the right FP for the bolts along the manifold to the gasket.) I did not do this because I'm old school and like making more problems for myself down the road! 😎 I get everything back together, add coolant because I lost so much during the repair and reconnect the negative lead to the battery. I start it up, little rough upon start up tell everything got flowing again, and no dash lights on. I proceed to drive a couple miles to make sure everything is safe. It seems ok, No check engine/Trac cel coming up. I shut the car off, cleaned up my mess from the repair and started it back up. Both Lights back up solid check engine/trac. since I did the repairs at another location about 23 miles away, I drove home with the lights on the dash instead of resetting it. Drove fine, shifted fine all the way home. I shut it down upon arrival, check under the hood at the coolant level, and the overflow was empty. I assumed this would happen because the amount I lost during the repair and the system restablishing itself. I removed the radiator cap, it took about a 1/4 quart, and then refilled the overflow tank to the full level. When I restarted the car to put it in the garage, it made a horrible continuous knocking noise from the motor, and sounded like a steel ball knocking around in the top of the manifold? The car became very sluggish, low idle and jerking in park, and upon acceleration? I put it in the garage and unplugged the negative lead to the battery. The next morning I came out reconnected the battery and again checked my work. I found I forgot a vacuum hose leading from the same bundle that lead to the intake,but not the intake vacuum hose, the small one that heads left under that small black round thing. I hook this back in, reset the computer again and had to take it to work. So upon restarting the car, the check engine light comes on flashing repeatedly and the engine knock was a bit less but uncomfortable. I had to drive into work this way, hesitating, jerking, check engine light flashing, then going back and forth to a solid light again. I drove it to auto parts store after work to rerun the codes....
* P1155, P1135, P0305, P0325
*P0305 Misfire on Cylinder 5
* P1155/P1135 - Upstream and Downstream
O2 Sensors
*P0325 - Random Misfires
So I swapped out the Front O2 Air/Fuel Sensor (B1 S1, The one a put in 7 months prior. The parts store let me return it and gave me a new one.) I wanted to rule this part out. I got six new NGK plugs and one new ignition coil for cylinder 5. I changed out all the plugs and one plug in Cylinder 5 had the gap pushed all the way into the ignitior of the plug? How does this happen??? All the coils looked pretty good just looking them over except Cylinder 5's looked oxidated and not as clean, so I swapped this one out with a new coil. I also cleaned out the MAF Sensor just in case, this was fairly dirty also. Still sluggish and sputtering at about 65MPH or just randomly and will not shift into 4th on the highway and running at about 4.5 on the Tach. Check Engine/Trac Lights still on the dash, and the only thing I can think of is to clean the throttle body and replace the Downstream O2 Sensor. I am scared to pull the codes again since I am already out like $500 on this one. I guess I have saved about $2500 in labor costs doing this myself, but I will pull the updated codes for this tomorrow and keep you all updated. Any help with this will be greatly appreciated. This has been a real job, and have about 10 hours of labor into this whole process. I must say I have learned a great deal about this car from the experience though. T
You should get an OBD 2 scanner to monitor the engine as it's running.
I was actually considering that. I scanned the codes at the parts store again last night, and only have a P0171 - Bank 1 System too lean. I am at the point where I need some solid data. I know Amazon has some if them scanners pretty cheap. Any brand work good with iPhone. I clean out the MAF sensor real good and checked my hoses today. Gonna reset the Code and see how it drives again tonight. Thx, T
You mentioned that the car is origanly from the west coast. If it's a California speced car than some components would not be the same as for a Federal speced car. A/F sensor is such an example.
So make sure that any component that you replace is speced for YOUR car.
i think there is a label under the hood indicating which specs your car meets. If you can't find one, than a Lexus dealer should be able to tell you based on the serial number.
ALSO. Aftermarket Knock Sensors seldom work properly in our cars. Hope you got OEM ones.
If Denzo parts are available, that is what I have been using. The car was actually purchased by the previous owner here in the Midwest, but the guy used to drive it back and forth to CA(Snowbird). I ran the scan tool again last night. P0171, I cleaned out the MAF sensor by hand and made sure it was free of all oil and debris from the air box. Changed my oil, and checked all my vacuum lines for air leaks. The car is running good, it is also now shifting to also on the freeway and running at about 2.5 on the Tach at about 70MPH. After I reset the code, drive for about 20 miles, I'm getting a slight hesitation before a solid CEL/Trac Off light. It feels as if its starving for air. The front Air/Fuel Sensor I just replaced on B1 S1 is also a Denzo Part. The rest of the parts I have replaced seem to have worked, and if your guys think replacing that rear O2 sensor by the firewall could fix this issue I will replace it, but I was under the assumption this is down stream B2? Thanks for your suggestions guys, I think I'm narrowing this issue down. T
Last edited by tony2000LE; 08-12-16 at 05:36 AM.
Reason: Forgot something
Bank 1 is the cylinder head closest to fire wall (which contains cylinder #1)
Sensor 1 is the A/F sensor
Sensor 2 is the O2 sensor
Starting where the cylinder head and the exhaust manifold meet, follow the exhaust path until you see a sensor - that is the A/F. Continuing on that path, (on my 2002 es) there is a pre-cat, then you will see the next sensor on that specific exhaust piping side which is the O2 sensor.
The computer reads the raw exhaust via A/F sensor, then reads it again after passing through the pre-cat via the O2 sensor.
The schematics in the FSM and online parts sites can be deceiving. I find it best to get under there and visually see the system following the path. The dreaded Bank 1 Sensor 1 is buried between the engine and firewall.
• Replaced both Knock Sensors/ Harness/ Gaskets
• Replaced both Air/Fuel Sensors(Left/Right)
• Replaced PCV Valve
• Replaced 6 Spark Plugs(NGK's)
• Replaced Ignition Coil on Cyl #5
• New Oil, Filter & Air Filter
• New Transmission Fluid
• Cleaned MAF, Air Box, Throttle body control valve and lines
& have check all fluids, hoses for leaks. When I reset the CEL/ Trac
the car is running and shifts great. The CEL usually pops up after the second
time I restart the car. It does shift and run good, but has a strong gas odor
coming from the exhaust. After cleaning out the idle control valve last night,
I have double the acceleration power now.
I am still getting the p0171 code after doing all this? I have about $750 in replacement parts into the thing. Is it worth replacing the MAF Sensor? I still have a gas smell from the exhaust, and I am at a loss on this. PLEASE HELP??? T
Last edited by tony2000LE; 08-22-16 at 08:12 AM.
Reason: Updated
Thanks Again, for all your help and suggestions on these issues. T
* UPDATE *
So yesterday I replaced the MAF Sensor, Reset the CEL/TRAC Light. I am happy to report that the lights are off, and the idle is running smoothly at about .075 on the TACH with no spikes. I had originally cleaned out my old MAF, and must have made a defective part even worse? For anyone getting a solid CEL/TRAC on the dash and pulling codes P0171, or the Air/Fuel Sensor code, I would highly recommend changing out the MAF sensor first, as this is most likely the problem. Although I replaced multiple parts on this car over the last few weeks based on my codes, my car has very high miles, and they were probably on the verge of failing anyway at some point in the near future, and the car is running and driving much better since I bought it. 2000 Lexus ES300 PE - 263,801 Miles. Tony
lol, I did look in the manual on that dash light. It could be that the green square around the "D" letter on my instrument panel does not light up, or some bulb in the rear? I checked all my lights and signals though, and everything seems to be working properly as far as I noticed? Thanks for reminding me of this, but now I'm broke from repairing everything else, so it will have to wait�� T
okay, let me tell you what happened in my case. The electric cable in the trunk (some of the wires) got cut from opening/closing the trunk over the years. So the bulbs on the trunk (and the number plate light) only were not getting power.
This is when the headlights are ON. Check to see if that is your issue too
I usually have the lights set to auto, but I did turn it to the ON position to check the rear lights, and they all seem to be working? The wiring harness in the trunk looks in good shape. Is the high tail light constant with the lights in the ON position, or does the brake need to be applied for it to light up? Thx, T
08-11-16, 06:11 AM
2000 ES300 Knock Sensors Replaced, Running Rough, Multiple Codes, Troubleshooting
