Well the other night I was coming home, and while getting on the on ramp my CEL came on for about 15 seconds then went off, and never came back. Then the next morning it happened again (when I was getting on to the highway it came on for 15 seconds). Today I hooked up my scan tool, and the only codes I could get to pop up were code 41 - EGO not switching, lean exhaust (bank 1). That one I was told could be fixed with a new o2 sensor. The other code is: code 32 - EGR (EVP/EPT) signal too low, and I have no idea on where to start on this one. I have also noticed that when the truck is in drive, but with my foot on the brake it stumbles pretty bad. I figured it was that the pulgs probably needed to be changed, but now I don't know.

 

If the EGR is sticking it often can make the engine stumble at idle.

Check the hoses and the steel pipe carrying exhaust gas to the EGR. Any of these may be crumbled or disconnected. These are usually easy fixes and if it is a hose, really cheap. Be careful of the steel exhaust pipe, they can be brittle and crumble in your hands.

If you have a vacuum pump like a Mityvac, you can put a vacuum on the EGR diaphram and see if it operates with and without vacuum, you could even use your fingers to press from the underside(only when cold). SHould stumble as you pull vacuum. It should then stop stumbling when the vacuum goes away.

If the engine is still stumbling after no vacuum, then the valve may be sticky. If the vacuum pump does nothing then the diaphram may be leaky. If it just stumble no matter what, then probably the valve is plugged up.

For problems with the EGR, usually the easiest fix is to just replace it. SOme EGRs can be cleaned with some carbon cleaner. SOme even have a little window that you can unscrew so you can get at the EGR spindle or rod that operates the valve.

If you remove the EGR, DON'T lose the thin steel shim that some of them have. They are a beach to find if dropped and most EGRs don't come with a new one.

One last thing I can think of, is that many of the EGR systems have an electronic sensor that determines if there is proper feedback from the EGR valve. These can go bad and need to be replaced. I am suspecting this might be your problem but I do not know your engine. I have only had one engine need this and the part was called a PFE pressure feedback emitter. Maybe that is your EVP/EPT?? Not sure how to test these without a good tester, I love SUN testers, but don't have a few thousand$$.


Good Luck,

Jim Henderson

 

Thanks man. I'll check all that stuff in the morning. By the way the engine is a 5.0. If that changes anything.