I've got a problem with my EGR valve and it is giving me an SES light. I had totally forgotten that this showed up last year and that I had used TunerCAT to turn off the light for emissions. I'm getting around 13MPG and am suspecting that the EGR may be the culprit. I'm about to perform some vacuum testing to figure out if it is the valve, solenoid or both, but here is my question.

Can I simply have the EGR programmed out and if so will this help my gas milage, if in fact the EGR is what is causing the poor mileage?

Thanks in advance!

Joe

 

A leaking EGR valve can cause the engine to run rich. Whether its causing the problem as large as yours is only a guess. When working correctly, EGR may acutally help increase gas mileage, acting as a mini "displacement on demand" system. Its really a useful system, but everyone seems to be in a rush to delete it in the belief that anything related to "emissions" can't be good for your engine.

 

will the egr effect a certain bank?

 

No.... the EGR port is connected to the entire plenum, not just one side.

 

Thanks Fred. I was hoping you'd chime in, as I've seen your comments on this topic in other posts. I'm about to go test it and will figure out what's failing so that I can replace it, leaving the system intact.

Thanks again!

 

So, I used Shoebox's testing write-up to test the EGR. (Thanks Shoebox!)

With the car running and my MityVac attached to the EGR, the valve doesn't hold any vacuum and the idle doesn't change at all, so I suspect that the EGR valve is bad.

I also checked vacuum coming off the intake, going to the EGR solenoid. With the engine running the vacuum guage reads anywhere from 25 to 30 at around 2000 RPM. Is this too high?

I also checked the vacuum on the side of the solenoid going to the EGR valve and it was around 10. Applying vacuum to one side of the solenoid while checking the other side yields the same amount of vacuum I am applying.

So, I guess my questions are this....

1. DOes it sound like the EGR valve needs to be replaced?

and

2. Is the vacuum coming off the driver's side of the intake too high?

 

What units does the gauge measure in? There is no way an engine can pull 30"Hg (that's close to a perfect vacuum, hard to achieve with a water ring vacuum pump). You would see some high vacuum numbers if you were running the engine at 2,000rpm and slammed the throttle blades closed, but only for an instant.

Just measure the engine vacuum at idle, without playing with the throttle. At idle a stock cam should pull 20-21"Hg. When you apply 12V to the EGR vacuum solenoid, you should see the same 20-21"Hg at the end of the vacuum line that connects to the EGR valve.

But if you can't move the EGR valve open with the Mitey-Vac, it sounds like its broken.