I just purchased a used 1996 A4 2.8. A CEL came on after driving for about a week. I went to Advanced Auto Parts and code P0401, EGR Flow Insufficient was detected.

I noticed that this model required at least 91 Octane, it has been driven approximately 300 miles on 87 Octane. Could this be the reason for the CEl and Code?

Or is there a problem with the EGR valve, or maybe just a dirty EGR valve? How can I check this myself? I have some experiecne working on a 944, but this is the 1st Audi I have owned.

Any advice would be great, Thanks.

 

Cleaning it won't hurt.

 

That was one of the last problems I was exipercning before I sold my 96.


Fault O2 Sensors can cause it
Dirty EGR Passage
Faulty EGR Valve

http://search.audiworld.com/search.html
https://www.audiforums.com/search.asp

Type in 'EGR" thier is a couple write-ups on how to clean it.

 

yep ill go with cleaning the EGR valve its probably sticking due to carbon build up which would not allow the solenoid to get a signal also check the wiring

 

Make sure you run at least 91 octane, if not 93.

87 will cause all kinds of problems, these cars require 91 at least.

 

only turbos i thought?

MANUAL SAYS 87 for 96 v6 engines.

 

87 Ron fuel is cheap and MPG suffers (car under performing) its that simple, I personally recommend minimum 95 Ron