Thanks in advance for your time. I SES light comes on every once in a while. I ran the codes and its a EGR Malfunction. I had the EGR Valve tested at a shop and they said it was functioning fine. I than talked to another mechanic and he explained my situation exactly, no decrease in perfomance, but light pops on while crusing on freeway occasionally. He said that the EGR Valve probably has build up from the 153,000 miles on the car. He wasn't really clear on how to fix the problem, he said something about carburetor cleaner or something, but I didn't really understand. Any advise on how to clean up the EGR without taking the car apart??? Thanks.

 

The EGR valve is attached to two studs on the back of the intake manifold. A bit hard to reach, but you take off the two 1/2" (or 13mm) wrench-size nuts, and the valve can be removed from the intake. You spray the pintle on the valve with solvent to remove the built-up carbon.

But you may still have a bit of carbon caked in the intake manifold, and that's a little harder to get out. First, you can only see it with a mirror, and then you don't want to drop chunks of it into the manifold.

It would probably be worth pulling the EGR valve and cleaning only that to see if it helps with the problem.

Courtesy of Shoebox:

http://shbox.com/1/egr1.jpg

 

Thank You very much, I appreciate it.

 

If you have less than a 100,000 miles on your car and your ses light is on reading a p400 code than you can take it to a chevy dealership and they will fix it for free. It is not a recall it is called a special policy adjustment and it will not show up if they look it up as a recall. I just got mine fixed last week. I think the special policy # is 00096

 

Nevermind, I just read that you have over 100,000 miles

 

This sounds really familiar.

If I drive for about 15 mins, and stay between 70 and 80mph the whole time... my car gets REALLY SLUGGISH, and I get an SES that is somethin to do with EGR. I am OBD1 (93 m29 m6 ta). Do you need to fix the egr system, or would taking it out in the PCM fix the problem also? I mean is it really making the car sluggish or is that a computer response to a clog?