Originally posted by ContourKev:
Update!!!

Now my automotive teacher stated my gas milage shouldn't be thrown off much with a bad EGR Valve (not opening) How would this effect my engine? To me EGR is a peice of [censored]... I'm debating wheater to go buy a new EGR Valve now, or wait till Union stops stealing money from my paycheck....





With a nonfunctioning EGR, the computer compensates with a slightly richer mixture, but it shouldn't make too much of a difference with mileage. With EGR, the engine can run with a bit less gas since exhaust gases are inert; with the EGR valve open, it's like having your combustion chambers destroked. EGR came about in the '70s since carburetors were being set leaner and leaner for increasingly stringent CARB standards. The resulting hotter exhaust meant formation of NOx, so inert exhaust gases were used to cool down the the combustion cylinder.

Yeah, it's a PITA. On my '78, I'm just glad that the EGR valve is easily accessible.

Po

Po 1995 Mercury Mystique GS: Zetec 2.0L I-4, CD4E 1978 Ford Thunderbird Town Landau: 351M (5.8L V-8), FMX Coming in 2007 -- 1986 Jaguar XJ12 Sovereign: 5.3L High-Efficiency V-12, GM transmission