91 LS400 - check engine light is on... code 71
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
91 LS400 - check engine light is on... code 71
Update - Problem fixed... thanks for all of the replies. The shop cleaned the EGR system and all is well now... charged $49.00 + tax. Almost dont want to sell it now.
Oh well.
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?
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.
Its running better than it ever has since I have owned it, so its strange.
Oh, finally have the steering problem almost taken care of, now this.
Thanks and Merry Christmas
Oh well.
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?
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.
Its running better than it ever has since I have owned it, so its strange.
Oh, finally have the steering problem almost taken care of, now this.
Thanks and Merry Christmas
Last edited by 91LS400LEX; Jan 8, 2010 at 05:46 PM.
You made a mistake running the air hose directly into the front of the intake. The air is now bypassing the throttle body, as a result, you are raising your idle and increasing fuel consumption. INSTEAD, just use vacuum caps for both points.
As for the EGR idle 71, there is something wrong with your EGR system. Make sure there is no vacuum leaks from your vacuum modulator. I thought my EGR valve was toast, but then I tested it and found it works fine. Turns out it was a very small crack on the VCV, replaced it and it was good to go.
As for the EGR idle 71, there is something wrong with your EGR system. Make sure there is no vacuum leaks from your vacuum modulator. I thought my EGR valve was toast, but then I tested it and found it works fine. Turns out it was a very small crack on the VCV, replaced it and it was good to go.
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
Thank you Avalon. Well, apparently I was told wrong when I ran this vacuum hose when I blocked the ICV valve. I was told several different things (how to run it, etc) and now that you mention it, my MPG's had went down. I was getting 20-21 consistantly, but it seemed like it had went down. I went out earlier to cap the ports, but could not find the caps I had. I will definitely get some tomorrow and cap them and do away with the hose.... hopefully my MPGs will go back up and I was hoping this was my CEL issue was well. Apparently not?
Thanks for that EGR info, but its all like Chinese to me... I dont know what to do. Where is it located and how to I clean it? Some site on where I can get step-by step info on how to do it or someone out there tell me? A new one is almost $200. How do you remove it and how do you clean it?
I have someone that wants to buy the car, perhaps on Tuesday and I would like to get it up to par by then. I dont want to have to reduce the price, or lose out on selling it because of this... you know a CEL scares some people away.
Thanks in advance.
Thanks for that EGR info, but its all like Chinese to me... I dont know what to do. Where is it located and how to I clean it? Some site on where I can get step-by step info on how to do it or someone out there tell me? A new one is almost $200. How do you remove it and how do you clean it?
I have someone that wants to buy the car, perhaps on Tuesday and I would like to get it up to par by then. I dont want to have to reduce the price, or lose out on selling it because of this... you know a CEL scares some people away.
Thanks in advance.
Last edited by 91LS400LEX; Dec 25, 2009 at 07:34 PM.
If you look at the picture, I labeled one of the nuts that needs to be removed with the black arrow. There is 4 of them holding the EGR on. You will need to remove VCV, EGR modulator, and the bracket that holds all of them plus the vacuum tubes. It takes only about 20 minutes, assuming that your EGR is clogged.
To clean, use some MAF cleaner or brake cleaner and a light brush, up to you.
To clear the CEL of the stored code, pull the EFI fuse while the car is off, then replace it.
Picture is courtesy of LexLS.
To clean, use some MAF cleaner or brake cleaner and a light brush, up to you.
To clear the CEL of the stored code, pull the EFI fuse while the car is off, then replace it.
Picture is courtesy of LexLS.
Last edited by avalon42; Dec 25, 2009 at 09:58 PM.
Lexus Test Driver
Joined: Apr 2004
Posts: 1,265
Likes: 9
From: MA
The black cover on the top of the EGR vacuum modulator pops off. Right below it is a small filter that you can clean. No need to take anything apart to clean it. Just pop the black cover off with a small flat head screwdriver.
What Jim meant to say that's what you do if you want to clean the EGR modulator filter, not the EGR valve itself. You can follow directions from LexLS: http://www.lexls.com/tutorials/emission/egrfilter.html
To clean the EGR itself, you would follow my original steps.
To clean the EGR itself, you would follow my original steps.
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
Thanks Jim and Avalon. Well, the filter only defintely sounds easier and more along my lines of know-how. lol. I will clean it.
However, 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. Thanks.
However, 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. Thanks.
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Thanks Jim and Avalon. Well, the filter only defintely sounds easier and more along my lines of know-how. lol. I will clean it.
However, 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. Thanks.
However, 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. Thanks.
Watch for the light as it may come on after about 20-40 miles or so.
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Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
Thats when I will revert to a strip of black electrical tape over the light if this other stuff dont work. 
, but I am not a devious person and I could not live with myself. I hate to do that and it will only be as a last resort.
I guess I could file bankruptcy. Its not like the car is running poorly. I have known people drive cars with the CEL's on for years and never no major woes, but when you want to sell a car, a CEL is a major turn off for a lot of people.
I have give this car my all and done all I can. It has almost driven me into bankruptcy, which is sad, because major mechanics, this car is solid as a rock. I feel the engine, transmission and body will last 250K+ more miles. Its the little things like this that have dimed me to death.... fix one thing then almost instantly something else happens.
, but I am not a devious person and I could not live with myself. I hate to do that and it will only be as a last resort. I guess I could file bankruptcy. Its not like the car is running poorly. I have known people drive cars with the CEL's on for years and never no major woes, but when you want to sell a car, a CEL is a major turn off for a lot of people. I have give this car my all and done all I can. It has almost driven me into bankruptcy, which is sad, because major mechanics, this car is solid as a rock. I feel the engine, transmission and body will last 250K+ more miles. Its the little things like this that have dimed me to death.... fix one thing then almost instantly something else happens.
Last edited by 91LS400LEX; Dec 27, 2009 at 12:36 PM.
Thats when I will revert to a strip of black electrical tape over the light if this other stuff dont work. I hate to do that and it will only be as a last resort. Its not like the car is running poorly. I have known people drive cars with the CEL's on for years and never no major woes, but when you want to sell a car, a CEL is a major turn off for a lot of people.
I have give this car my all and done all I can. It has almost driven me into bankruptcy, which is sad, because major mechanics, this car is solid as a rock. I feel the engine, transmission and body will last 250K+ more miles. Its the little things like this that have dimed me to death.... fix one thing then almost instantly something else happens.
Its not like the car is running poorly. I have known people drive cars with the CEL's on for years and never no major woes, but when you want to sell a car, a CEL is a major turn off for a lot of people. I have give this car my all and done all I can. It has almost driven me into bankruptcy, which is sad, because major mechanics, this car is solid as a rock. I feel the engine, transmission and body will last 250K+ more miles. Its the little things like this that have dimed me to death.... fix one thing then almost instantly something else happens.
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
Good thing I dont live in California. What if there was a blown bulb in the check engine light socket? Is that a lawsuit too?
The CEL has been illuminated on my moms car for 8 years (code says its the o2 sensor and we have replaced it 5 times and it never goes off) and its never caused any issues.
Seriously, as I mentioned, I would hate to revert to that and I have never done anything like that before and when it comes down to it, I probably would not be able to make myself do it, even though I am sure many would. Also, I dont think its anything serious, but when SOME people see a check engine light on, they think the car is about to blow up and it loses about 80% of its value. It would not even suprise me at the # of cars out there that this light may even have a blown bulb on.
I have driven the car more and the light didnt come on. I bet it was that vacuum leak. I also checked that EGR filter and it looks like new.
What if there was a blown bulb in the check engine light socket? Is that a lawsuit too? The CEL has been illuminated on my moms car for 8 years (code says its the o2 sensor and we have replaced it 5 times and it never goes off) and its never caused any issues.
Seriously, as I mentioned, I would hate to revert to that and I have never done anything like that before and when it comes down to it, I probably would not be able to make myself do it, even though I am sure many would. Also, I dont think its anything serious, but when SOME people see a check engine light on, they think the car is about to blow up and it loses about 80% of its value. It would not even suprise me at the # of cars out there that this light may even have a blown bulb on.
I have driven the car more and the light didnt come on. I bet it was that vacuum leak. I also checked that EGR filter and it looks like new.
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
Drats! It came back on last night while me and some friends were coming back from dinner. Again, I was on a highway, going about 57 mph.
I am going to attempt to remove the EGR. Hope I dont screw anything up.
I am going to attempt to remove the EGR. Hope I dont screw anything up.
Thread Starter
Lead Lap
Joined: Nov 2007
Posts: 401
Likes: 3
From: Tennessee
There was a hose that was not completely up tight against a connector. It didnt seem enough to make an air leak though, but you never know. I pushed it up all the way against it the plug and reset the light. We will see.
It may be something for the next owner to deal with... someone will be getting a heck of a deal on this car anyway.