Engine+trac Lights On P1135, P0171 And P0172

[way2007]

Hi Guys,

I am a newbie, have a 99 es300 with 135k miles on it. My engine+trac light came on 3 weeks ago and it went off within couple days . It resurfaced again a week ago and went off within a day. Now since last few days it came back on and i took it to Autozone to get the codes. It was P1135 , P0171 and P0172 all together.The Autozone guy printed out the description of all the above errors. My Gas cap is tight.Checked the air Filter and its not that bad. I do notice the car as if its having breathing problem when i slow down to make a stop.It doesnt die or anything like that. Also my mileage is low after this.

About 9 months ago i replaced 3 coils for misfires and replaced all the fuel injector.

Can some one please tell me what could be wrong here.

Can someone please pin point to me if its a Mass air flow sensor or if its O2 sensor is the problem. I hate to buy both if its not required.

Should i have it scanned by a professional with a computer for more indepth diagnostic report to pin point the failed component? (they charge 50$) .

Also can someone please tell me where these are located (o2 sensors on bank1 sensor 1 or MAF) on the car if i can do it myself and what tools do i need.(to replace o2 sensor or MAF sensor).

If i have to clean the MAF sensor can i do it myself and what do i need to clean it.

Where can i buy these generic parts if anyone can reccomend to put on them ?

Also if its o2 sensor which o2 sensor should i buy , is it pre cat post cat , front or rear (i am confused)

Appreciate all your help in this matter.

aj

[way2007]

correction above .I meant to say i replaced all Spark Plugs (not fuel injectors) 9 months ago along with the 3 coils when i had the misfire problem.

[way2007]

Hello Guys,

can someone tell me how to go about finding what is causing the issue, can GAS filter(is this fuel filter he is referring to?) trigger this error codes, one of the mechanic i went to suggested we replace gas filter since it hasnt been replaced in the last 2 years(20k miles). Do you guys agree on that?

thanks

[blk_on_blk]

It sounds like one of the O2 sensors, for those are all air/fuel mix codes. I believe the P1135 is a bank 1, sensor 1 Air/Fuel heat sensor. The other codes refer to a 'lean' mix detection. Here's a link to a guy who had a similar problem (it's in an RX300, but very similar layout). It sounds like replacing the sensor (or both) will be your fix: http://www.clublexus.com/forums/showthread...p=15&page=2

[way2007]

Thanks, Anyone here can point me to how to replace the GAS fuel Filter for the 99 es 300 ?

[Lexlogic]

P0171 and P0172 Mass air flow sensor. Just use Mass flow sensor spray cleaner. It could found at auto store not carb cleaner spray. MAF is located next to the air fliter housing, held down by two screws. Disconnect electrical wiring and two screws then lift up MAF to spray clean. Don't forget to reset code if engine check light is "ON" then drive you car a least 4 days at normal driving.

[way2007]

P0171 and P0172 Mass air flow sensor. Just use Mass flow sensor spray cleaner. It could found at auto store not carb cleaner spray. MAF is located next to the air fliter housing, held down by two screws. Disconnect electrical wiring and two screws then lift up MAF to spray clean. Don't forget to reset code if engine check light is "ON" then drive you car a least 4 days at normal driving.

Thanks , cleaned the MAF but the code popped back on after a few miles. Can someone tell me how many MAF or 02 censors this 1999 es300 has and where they are located at ?

[mike411]

i just had my problem with check engine light and trac control removed.... P0171.... I was thinking to go to dealer and have code verified, but decide to do what my friend told me. "clean mass flow sensor with spray cleaner"... First I though I have to replace O2 sensors and spend 300$ for parts and service, but cleaning this sensor fixed the problem.

this is the link

http://www.lexusownersclub.co.uk/knowledge...id=152&c=11

Total cost of fixing the problem = 6.99$

:D

:D

P0171 and P0172 Mass air flow sensor. Just use Mass flow sensor spray cleaner. It could found at auto store not carb cleaner spray. MAF is located next to the air fliter housing, held down by two screws. Disconnect electrical wiring and two screws then lift up MAF to spray clean. Don't forget to reset code if engine check light is "ON" then drive you car a least 4 days at normal driving.

Thanks , cleaned the MAF but the code popped back on after a few miles. Can someone tell me how many MAF or 02 censors this 1999 es300 has and where they are located at ?