Very low Idle (1999 Lexus Gs400)
01-23-14, 12:00 AM
#46
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You should change all 4 bro. That's my advice. But hey, it's your car. The gaskets will definitely do justice too. You'll feel the difference. And here's a pic of my badboy
The first pic was taken last year. And the second was taken the first summer I had it almost 2 years ago. Still looks the same. Nothing external changed. Just internal things to do with the engine. Plan on taking it to get my cross drilled rotors and MOOG inner + outer tie rods & lower ball joints soon. Plus an alignment. Maybe timing belt service in the summer as I'm approaching 100k. Plus a few lil things like screws around the fender I need to g
et then I'll feel complete. I can move on to my next investment :-).
Those picts are when I first got the car 2 years ago. Now it has the rims u saw on first pict. Now concentrating on top shape with motor and components
01-23-14, 10:19 AM
#47
Lexus Test Driver
It's looking good bro! I like it! The red in the engine makes it look very unique. I think it looked good with either set of rims btw. I bet it looks much cleaner with the OEM headlights. And yeah man, performance and longevity is what I'm focusing on as well. Just got it back from the shop this morning. Turned out I was told I had a defective o2 sensor but I really didn't. The wiring harness from the car to the actual sensor was corroded. Luckily my guy was able to pull it off and rewire it, make it work correctly and did it in a durable way. Only charged me $75. Can't complain. CEL is off for new. I hope it stays off. I replaced everything OEM. Can't wait to do more stuff all around the car.
01-23-14, 10:48 AM
#48
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It's looking good bro! I like it! The red in the engine makes it look very unique. I think it looked good with either set of rims btw. I bet it looks much cleaner with the OEM headlights. And yeah man, performance and longevity is what I'm focusing on as well. Just got it back from the shop this morning. Turned out I was told I had a defective o2 sensor but I really didn't. The wiring harness from the car to the actual sensor was corroded. Luckily my guy was able to pull it off and rewire it, make it work correctly and did it in a durable way. Only charged me $75. Can't complain. CEL is off for new. I hope it stays off. I replaced everything OEM. Can't wait to do more stuff all around the car.
01-24-14, 06:16 PM
#49
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Haven't get the o2 sensor or cats gaskets. But today I come across the tire shop and somenthing make me feel to get a new battery. Like I said before I had the feeling the my battery was weak. Anyway got a new battery and surprise . OMG!!! guess what. My idle its way better and normal. Drove the car like 10 miles to make sure the idle got corrected. And it did. What a difference. Good idle. Lots of power. Like a new car seriously! !!. Im surprised. Anyways here is the pict from actual idle. Tomorrow I should get the sensor and gaskets and I will update pn that
01-24-14, 08:58 PM
#50
Lexus Test Driver
URGENT UPDATE!!!!!!
Haven't get the o2 sensor or cats gaskets. But today I come across the tire shop and somenthing make me feel to get a new battery. Like I said before I had the feeling the my battery was weak. Anyway got a new battery and surprise . OMG!!! guess what. My idle its way better and normal. Drove the car like 10 miles to make sure the idle got corrected. And it did. What a difference. Good idle. Lots of power. Like a new car seriously! !!. Im surprised. Anyways here is the pict from actual idle. Tomorrow I should get the sensor and gaskets and I will update pn that
01-25-14, 09:10 AM
#51
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Great news man!! I'm so glad to hear this! If I'm not mistaken, I told you my battery increased my idle slightly too a few posts ago. Very good! You will see after you put on new gaskets and secure air leaks how nice the engine will respond. It just feels better. And if you have a 430 like me, yes the 2 downstream sensors will need to be accessed under carpets. And down out thru the bottom part of the doors. If I find a diagram I'll post it for you bro. I think the 400 is the same too. I'm just not too sure about 300s and where the actual o2 sensor locations are.
And yes I have a 400 and if u have the diagram will ve awesome
01-26-14, 01:45 PM
#52
Lexus Test Driver
I'll post the diagram next time I get chance to hop on here bro. Also btw thought I'd share this. My CEL has been off since I picked up car this recent Thursday morning. I've noticed a GREAT difference in consumption of gas. I know this because I daily drive my car. With those new o2 sensors, it's really made a difference.
01-27-14, 07:28 AM
#53
Lexus Test Driver
Here's 2 diagrams you might need. If not for you, then for at least your mechanic. Either or, you might find this helpful. One is the B1 S1 & B2 S1 locations of the o2s and the other is a diagram of the whole exhaust... when I find the downstream o2 diagram I'll post it bro!
Hope you find this useful!
Hope you find this useful!
01-27-14, 07:34 AM
#54
Lexus Test Driver
https://www.clublexus.com/forums/per...placement.html
Here's another helpful link. Its for a DIY for the downstream sensors on a GS300.... Yes I know that's not your model car but until I find the correct diagram for your GS400, this will help give you an IDEA of what needs to be done to replace the 2 downtream sensors. It's practically THE SAME as GS400 & GS430. The first pics SHOW YOU how to take out the carpet and locate o2 connector and all that good stuff. Hope this helps as well!
Hey I also noticed in your pics that you have an intake... After reading a few threads on these mods, you should make sure all the wiring from your intake to the ECU is done properly cuz I've read allot of members suffering from "poor idle" as a result of that. Just thought I'd mention. If that helps at all.
Here's another helpful link. Its for a DIY for the downstream sensors on a GS300.... Yes I know that's not your model car but until I find the correct diagram for your GS400, this will help give you an IDEA of what needs to be done to replace the 2 downtream sensors. It's practically THE SAME as GS400 & GS430. The first pics SHOW YOU how to take out the carpet and locate o2 connector and all that good stuff. Hope this helps as well!
Hey I also noticed in your pics that you have an intake... After reading a few threads on these mods, you should make sure all the wiring from your intake to the ECU is done properly cuz I've read allot of members suffering from "poor idle" as a result of that. Just thought I'd mention. If that helps at all.
01-27-14, 07:51 AM
#55
Lexus Test Driver
Ok I found it! BTW, here's a link also to DIY on the o2 sensors to a LS430... It's almost the same engine as the GS430 IF NOT THE EXACT SAME. And pics of the actual process. Very similar to the GS400 in a way. If you know what your looking at.
https://www.clublexus.com/forums/ls4...t-numbers.html
Also here's the diagram as promised of the downstream o2 sensors. 
Good luck with your repairs and I hope this is all found helpful in the process bro!!
https://www.clublexus.com/forums/ls4...t-numbers.html
Also here's the diagram as promised of the downstream o2 sensors.
Good luck with your repairs and I hope this is all found helpful in the process bro!!
01-31-14, 10:59 PM
#56
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Ok I found it! BTW, here's a link also to DIY on the o2 sensors to a LS430... It's almost the same engine as the GS430 IF NOT THE EXACT SAME. And pics of the actual process. Very similar to the GS400 in a way. If you know what your looking at.
https://www.clublexus.com/forums/ls4...t-numbers.html
Also here's the diagram as promised of the downstream o2 sensors. Good luck with your repairs and I hope this is all found helpful in the process bro!!
https://www.clublexus.com/forums/ls4...t-numbers.html
Also here's the diagram as promised of the downstream o2 sensors.
Good luck with your repairs and I hope this is all found helpful in the process bro!!Yeah thank u so much for the diagrams. Now I know what to do to replace my downstream sensors. Well I had replace the gaskets and upstreams sensors. So far , way better idle. Better response and more power to the wheels
. Definitely my gaskets where bad. I have picts. I was Going to ask if inside of the cats they need it to be clean? Like spray some maf sensor cleaner or something. ??? Anyways I got all done now. Lol
Looking to do next: my other o2 sensors and valve cover gaskets, belt. And later down the road I will service tranny and gasket and engine oil pan gasket.
02-02-14, 08:54 AM
#57
Lexus Test Driver
Yeah thank u so much for the diagrams. Now I know what to do to replace my downstream sensors. Well I had replace the gaskets and upstreams sensors. So far , way better idle. Better response and more power to the wheels
. Definitely my gaskets where bad. I have picts. I was Going to ask if inside of the cats they need it to be clean? Like spray some maf sensor cleaner or something. ??? Anyways I got all done now. LolLooking to do next: my other o2 sensors and valve cover gaskets, belt. And later down the road I will service tranny and gasket and engine oil pan gasket.
02-13-14, 11:35 PM
#58
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So finally today I have time to work on my baby.
Today I replace the 2 O2 downstream sensors and valve cover gaskets with grommets.
I'm not trying to say I'm a mechanic try to be one but for me was easy and fun to do. It took me like 4 hours straight. I'm not gonna lie I was a little freak out to do it. But I done it and here is the info .
Just to let u know for some reason my the passenger side cover was cleaner and gaskets was so so.
My drivers was more dirty. More build up like gunk stuff on cover and gaskets more dried and leak stains around the bottom part. Why ??? Idk? 😞
Anyways I'm putting several picts and let me know any doubt.
First clean everything. I mean everything. I used brake cleaner.
The picts will help u but any question let me know. Btw I used rtv silicone around the blue grommets . Just to get them in place easily. Be carefull with the little tabs the holds them in place. Don't brake them. Be gently. Be patience. Yes u do have to replace the new washers on bolts. After all was done. Better response like a new car . Let me know if u do have a question.
02-13-14, 11:42 PM
#59
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So finally today I have time to work on my baby.
Today I replace the 2 O2 downstream sensors and valve cover gaskets with grommets.
I'm not trying to say I'm a mechanic try to be one but for me was easy and fun to do. It took me like 4 hours straight. I'm not gonna lie I was a little freak out to do it. But I done it and here is the info .
Just to let u know for some reason my the passenger side cover was cleaner and gaskets was so so.
My drivers was more dirty. More build up like gunk stuff on cover and gaskets more dried and leak stains around the bottom part. Why ??? Idk? ?de1e
Anyways I'm putting several picts and let me know any doubt.
First clean everything. I mean everything. I used brake cleaner.
The picts will help u but any question let me know. Btw I used rtv silicone around the blue grommets . Just to get them in place easily. Be carefull with the little tabs the holds them in place. Don't brake them. Be gently. Be patience. Yes u do have to replace the new washers on bolts. After all was done. Better response like a new car . Let me know if u do have a question.
02-15-14, 08:55 AM
#60
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Well looks like my idle is low again. FML!!! After all this I did. Pop the code again. P0171 system bank 1 too lean. After a lot a research they suggest to clean vvt solenoids and when I was trying to do this I discover on bank 1 vvt solenoid the wire to the conector it's getting strip out. So I will fix this to. And I order exhaust manifold gaskets. And throttle gasket too. And reseal the idle control valvle. Helpfully this will cure the code. I keep it updating