Disconnecting the EGR valve leads to EPA enforcement.

Dear Car Talk

Dear Car Talk | Apr 01, 1991

Dear Tom and Ray:

My 1980 Chevy V-8 with 120,000 miles used to hesitate at take off, and buck at speeds above 50 MPH. I discovered that when I disconnected the EGR valve, the bucking disappeared and the engine ran great. I asked my mechanic if that was OK, and he said he didn't recommend it. I did it anyway because a new EGR cost 60 dollars and the car ran great without it. My question is can I do that on my 1988 Chevy V-6 fuel injected car, or will the computer have a fit?

RAY: The answers are no, you can't, and yes, it will. The EGR (Exhaust Gas Recirculation) is part of the car's pollution control system. It cuts down on dangerous nitrogen oxide (NOx) emissions, which are a leading cause of smog.

TOM: It's true that a malfunctioning EGR valve could make your car buck and hesitate. But disconnecting it is not the answer. Fixing it is the answer!

RAY: Think about it this way, Steve. If you had a filter on your kitchen sink to purify your drinking water, what would you do if it got plugged up one day? Would you clean it out and put it back, or would you by-pass the filter and drink the contaminated water? Disconnecting your EGR valve is like making the rest of us drink dirty water.

TOM: So under no circumstances should you take the EGR off of your new Chevy. First of all, if the EGR is working, removing it won't make the car run any better. Second, your computer WILL have a fit, and will turn on the "check engine" light in protest. And third, tampering with the emissions system is a violation of Federal law.

RAY: Oh, and by the way, Steve, we forwarded your letter on to the enforcement division of the Environmental Protection Agency for further review. Hope you don't mind.

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One