Code 71

[jefftreece]

my engine check light and trac light are on I pulled the code and it is a 71 egr malfuntion. I have been doing searches and have not found any thing to solve the problem hope some body out there has some ideas on where to start. my car is a 91 ls400 with 153000 miles on it, the car runs the same with or without the lights on they do occasionly turn off . thanks

[92ls forhundo]

Hello Jeff, I have a 92 with 240,ish and i recently had that exeact same problem. I took the car to a trusted mechanic and it was solved by the replacement of " mushroom valve" . The offending valve is located on the driver side of the intake manifold. In my case my "mushroom" valve was just frozen with carbon. My mechanic said the part was about $45. no performance lost when it was bad but i wpould assume that it might cause failure when smogging the vehicle.

[jefftreece]

thank you for the info I will look into that.

[jefftreece]

anybody else have any ideas not exactly sure where the mushroom valve is? thanks

[92ls forhundo]

sorry for the bad description the right name is the "egr vacuum modulator". When you open the hood and you see the lexus logo on the manifold, on the right hand side you'll see too round valve-looking thingies(dont know how else to say it) with a bunch of hoses and such coming out of them, The one in the back is the egr valve and the one in the front is the "mushroom" valve, sorry for flaky description thats how a mechanic described it to me. Cheers.

[jefftreece]

thank you so much for the clarifacation. everybody here is so great. thanks

[tds]

I just fixed this on my 91LS400. It is called a Vacuum Modulator Valve and is part # 25870-50010 (part is around $150.00 CDN)

[pkshin]

I just fixed this on my 91LS400. It is called a Vacuum Modulator Valve and is part # 25870-50010 (part is around $150.00 CDN)

[]

Hi tds,

My 91 ls400 has same problem, code 71.

Did you have the code 71 and it is cleared after fix?

Any symptom you could feel while driving with the code 71?

I think the vacuum modulator filter can be easily cleaned by dusting off.

Thanks,

pks

[92ls forhundo]

I just fixed this on my 91LS400. It is called a Vacuum Modulator Valve and is part # 25870-50010 (part is around $150.00 CDN)

[]

Hi tds,

My 91 ls400 has same problem, code 71.

Did you have the code 71 and it is cleared after fix?

Any symptom you could feel while driving with the code 71?

I think the vacuum modulator filter can be easily cleaned by dusting off.

Thanks,

pks

[/quote

yeah after this was replaced the cel was gone and hasnt come back since. The part was about $50 here in so.cal.

[j.barleycorn]

Everything you ever wanted to know about code 71 (from the 1992 LS400 manual) trouble shooting section...

dtc71.pdf

Cheers!

[myf16]

My 1990 LS400 with 160k miles gave an Error 71. 

I can't find the source anymore, but someone online suggested replacing the clogged filter material under the EGR modulator plastic cap (pry it off) with a piece of this $2 Autozone material: duralast-breather-filter-cf4500dl. A 5-minute fix.

I think it's working. No more error code. 

[myf16]

My 1990 LS400 with 160k miles gave an Error 71. 

I can't find the source anymore, but someone online suggested replacing the clogged filter material under the EGR modulator plastic cap (pry it off) with a piece of this $2 Autozone material: duralast-breather-filter-cf4500dl. A 5-minute fix.

I think it's working. No more error code. 

Edited to add: The error code came back! More diagnosis needed.