Check Engine Light Illuminated!

[90LS400Lexus]

Update - ran the code and its "71" EGR system malfunction. It did not do this until I had the throttle body cleaned

On my drive home from work this evening when on the highway, my check engine light illuminated! It stayed on steady. The light stayed on, but the car is running better than ever now. To recap, I had the throttle body cleaned two days ago and the car runs so much better. Not sure if the issue is connected or not. I did disconnect the battery, restarted and it didnt come back on. I am wondering if it was just needed to be reset or something?

If it comes back on, can somewhere like Advance or Autozone read the codes on these cars?

Naturally this would happen three days before I likely had it sold! <_<

[landar]

They probably won't know what to do at AZ or AA.

You can do it yourself with this --> http://www.lexls.com/tutorials/intro/codereading.html

[90LS400Lexus]

They probably won't know what to do at AZ or AA.

You can do it yourself with this --> http://www.lexls.com/tutorials/intro/codereading.html

Thank you very much for that link! Seems very simple. If (or when) it comes back on, I will know what to do!

Well, I had already disconnected the battery to reset it and it didnt come back on just by starting it, but I am sure it will come on again. I guess I had cleared the code. I wish I had of waited. So strange it decided to do this shortly after I had the throttle body cleaned. Maybe he left a connection loose, or there is a vacuum leak at one of those vacuum lines he had disconnected in the process.

[Just hanging on]

On my drive home from work this evening when on the highway, my check engine light illuminated! It stayed on steady. The light stayed on, but the car is running better than ever now. To recap, I had the throttle body cleaned two days ago and the car runs so much better. Not sure if the issue is connected or not. I did disconnect the battery, restarted and it didnt come back on. I am wondering if it was just needed to be reset or something?

If it comes back on, can somewhere like Advance or Autozone read the codes on these cars?

Naturally this would happen three days before I likely had it sold! <_<

Sounds like your Lex might have experienced a "transient" failure in the emissions system. Transients will hit the MIL light and then go away. "Hard Codes" will illuminate the MIL and won't go away unless deleted by a scan tool.

[90LS400Lexus]

Sounds like your Lex might have experienced a "transient" failure in the emissions system. Transients will hit the MIL light and then go away. "Hard Codes" will illuminate the MIL and won't go away unless deleted by a scan tool.

Thanks. Well, due to wintry conditions the car has been setting at work since Thursday morning. I did go pick it up this afternoon though and did about an hour of driving and the light never came back on. Maybe it was trying to adjust to a clean throttle body. lol.

[90LS400Lexus]

Curses. Have I ever said how much I hate this car? <_< Fix one thing and something else crashes. Finally get the steering working most of the time and get its throttle body cleaned, then this happens.

Well the check engine light came on AGAIN today. Both times its came on is almost on the same spot on my drive home from work, when I hit 60 mph after the engine is fully warmed! I normally dont go over 55 on that highway, but there were two occasions I went over 60 since the throttle body was cleaned and both times it was on my drive back home. I went 65 today on the way to work and it didnt come on.

I guess all I know to do is to run that wire and see what codes is shown. I pray to God its not something expensive, but knowing this car, I am sure its going to be something outrageous. Funny thing is that it is running the best it ever has since I have owned it. Is it possible he left something loose after cleaning the throttle body? I guess I will know more when I get that code.

I cannot wait until I sell this POS.

I could always put a piece of black tape over the light (which is up in the housing), but I am not that devious. Too bad good things dont come to good honest people... all I have is bad luck with cars. :(

Merry Christmas everyone.

[OmarG]

pull the code, maybe its just some oxy sensors or somthin. http://www.lexls.com/tutorials/intro/codereading.html

Please stop calling your car a POS. its insulting :) The LS is a masterpiece of engineering. repairs are cheap compared to any vehicle of the same caliber and vintage...

Also...my sisters LS400 CEL randomly illuminated after i did a TB cleaning(2 years ago). Never checked the code, and it went away, came back, went away, never came back.

If the car runs the same, i wouldn't worry too much.

maybe reset the ECU too.

[90LS400Lexus]

Yeah, seems easy enough to check. I just havent had time.... work and holidays hectic. I bought some new wire and going to test it tomorrow.

LOL on the POS. I knew someone would say that. Its a good car - as far as major mechanicals go and it runs better now that it ever has since I have owned it, but frustrating this happened after I get some other things fixed and almost ready to sell. Oh no, it dont run the same... it runs so much better... its amazing and which is why it puzzles me that the light comes on now. Maybe the sensor plug is not in tight. I guess I will find out when I read that code tomorrow. My luck, no matter what it is, it wont be cheap. Never is with me. :(

How do I reset the ECU? I did disconnect the battery for awhile the other night... it (light) went off, but came back on the same stretch of road.

Seems like everytime I have a car I decide to sell, the CEL comes on.

pull the code, maybe its just some oxy sensors or somthin. http://www.lexls.com/tutorials/intro/codereading.html

Please stop calling your car a POS. its insulting :) The LS is a masterpiece of engineering. repairs are cheap compared to any vehicle of the same caliber and vintage...

Also...my sisters LS400 CEL randomly illuminated after i did a TB cleaning(2 years ago). Never checked the code, and it went away, came back, went away, never came back.

If the car runs the same, i wouldn't worry too much.

maybe reset the ECU too.

[OmarG]

gotta change that attitude buddy! an ls400 is easier to work on than a camry v6.

you already reset it when you unplugged the battery.

[90LS400Lexus]

you already reset it when you unplugged the battery.

I see. Well, it came on again about 3 days later, but not until I hit 60 mph. Oh well. :(

I will check it tomorrow if it dont rain all day.

May have to buy some tape for the sucker.

[90LS400Lexus]

Its a beautiful Christmas day, sunny and 60°, so I thought I would go out and check it.

Its flashing "71", "EGR system malfunction". What in the heck? What do I need to do now? The other LS site mentions something about pulling and cleaning the EGR valve or something, but really no details about it.

Remember, I plugged the ICV valve and ran a hose from the front of the intake to the air cleaner hose.... its making a hissing sound, when I squeeze it, the idle goes down some. I am wondering if this may be the issue and if I should just cap those ports? Strange it didnt do it though until I had the throttle body cleaned, but maybe now its getting too much air or something? I dont know. Any help appreciated. I hate to resort to black tape over the light.

On the other site, someone is saying it could be the EGR valve may have had something lodge in it and it needs cleaned or it has a vacuum leak, but I lean more toward the first part since this started after the throttle body cleaning... how do you remove the EGR and how do you clean it? A new one is almost $200! I cannot believe this!

[90LS400Lexus]

On the way home from work tonight I stopped at the auto parts store and bought some of those vacuum caps and capped off those ports on the intake ports.

This time the light didnt come on at the same spot I would get to when it would come on. Hopefully that was the issue.... time will tell.

Someone did tell me how to clean the EGR and then someone said how to do the filter only.

Thanks.

[91LS400Lexus]

Curses.... came back on tonight after driving about 35 miles on the highway.

[lexfourcam]

update on my issue guys. i plugged my maf in the morning and damn does the car run smooth and shift perfect. the only problem is it has a bad dead spot at about 1.5k-2k and it wont even go past 3k rpm. i'm thinkin the maf isn't opening properly. the check engine light also went of for about 20 seconds then came back on, and i didn't clear the codes.