I just got done working on the engine the other day and got everything running really nice. Took it out for a test drive on a cool night and man, it was running beautifully.

The next day, I took it out again... this time during the day and it was about 90 degrese outside. No problems... Until I was driving down the highway and after about 15 mintues the infamous "Service Engine Soon" light comes on. I get to my destination, and figure I'll need to check this when I get home. When I'm leaving again, the light is off, so I though maybe it was just a fluke.

Again, I get on the highway, and after about 15 minutes of driving the service engine soon light comes on. All the while, the engine is running perfectly fine highway speeds, low Idle, and all. Even starts without issue.

I get home, and check the code... I get the Code 32 (EGR System Failure) Since i'm not having a rough idle, hard starts, or anything, I'm not thinking the EGR is stuck open, but possibly stuck closed. So I'm guessing that when the engine commands for the EGR to open, it may not be opening.

I drove it to work this morning and the SES light did not come back on, however I don't generally drive on the highway to work, I usually take back roads (More fun in this car)

I will be checking the vacume hose tonight for holes... Aside from changing the hose, EGR valve, and cleaning the intake manifold... Does anyone have good tips on troubleshooting this code?

Mine would do the exact same thing periodically, on the highway. There was nothing wrong with the EGR. Sometimes it just throws the code, I think. I learned to ignore it. EGR is gone now, so is the code.
edit:From what I read, the ecm can command the egr to open from info received from the egr temp sw. If it doesn't open up comes code 32. Engine operation will basically not be affected AFAIK.

On mine the vacuum hose was bad. There weren't any holes, but it was not sealing proper. I just used a short section that I had and no more code!!

I agree a vacuum leak will cause this also.

Yea, lines first.

The way it's throwing codes is typical. If it's not the vac lines then you have to go thru the FSM chart.

Mine did that for a couple months, turned out to be the valve. But you never know until you run the checks.

You didn't say what year your 'Vette was, it makes a difference...

on my '91 it was the EGR solenoid -- which apparently is sometimes in production/available for sale, other times not...

Joe

Quote:

Good point! I was thinking it was a '92, but it is a '91.

http://www.corvette-guru.com/modules/ ... id=160538#forumpost160538

Sorry, the year is a 1991.

Mine used to have the same problem. I deleted all of that and had a chip made to get rid of the annoying light.

From what I read it is usually the EGR solenoid which bolts to one of the thermostat housing bolts. There is a very specific troubleshooting method in the FSM.

When I first got my 92 I had the same issue.
Was able to hook a small hand held vaccum pump to it and see that the little rod was not moving when applying vaccum.
Replaced the EGR valve and no anoying light.

My new build has it deleted

Thanks all... I will try working on this later this weekend. I'll you you guys posted on what happened and process.

Jaa1992, was it difficult to replace the EGR? My 1990 has failed emissions inspection twice. Im doing a fuel injector replacement job now for a host of other reasons. Wondering if I should replace the EGR just for kicks since I have the plenum removed already?

If it is of an unknown age, I would. Removing the intake on an L98 isn't fun...

On my LT1 I was able to use a gearwrench on the two bolts.
On your L98 I'm pretty sure you have to remove the plenum.
Not a lot of fun