EGR Valve

[Dcharn1]

I am told that my 95 Infiniti G20 might need an EGR valve. The emission light came on and a local auto parts store cked it and cleared the light on the dash. It has remained off. How does the engine react when it is bad? Thanks for any help.

[Twilight sentra tuner]

egr doesn't really affect engine performance. its mainly for emissions. egr recycles exhaust fumes back into the combustion chamber to cool off the overall temperature of the chamber itself. if an egr wasn't established, the temperature of the A/F mixture would become so hot where it would emit a very dangerous chemical into the atmosphere. can't remember what that chemical off hand. the egr was put in to avoid the a/f mixture form reaching that temperature and releasing that chemical into the atmosphere.

ur car will run fine without it but u won't pass emissions. and ur car may be more suspectible to overheating while going up a hill or pulling a heavy load.

[Q45tech]

EGR systems only work when engine is in low load cruise mode [1500-3,000 rpm] to improve mpg. Without EGR expect a 4-7% drop in highway fuel economy.

[Q451990]

I'm pretty sure that a faulty EGR will tend to cause more spark knock - since the exhaust gases are used to slow combustion (much like higher octane fuel).

An EGR code is more likely a problem with carbon clogged passages and/or a problem with the vacuum lines or their control solenoids - rather than a faulty valve itself.

Heath