it will cause a vacuum leak when the PCM tells the solenoid to open unless you plug the vacuum line that you pull off the EGR valve. depending on how long you leave it like that you will also get a CEL for EGR insufficient flow. other than that it wont hurt anything.
Daniel - TZT Performance '93 Mitsu 3000GT VR4 - 230K miles and counting
2000 Black SVTC #391 - sold '97 Contour GL Tutrbo - sent to the crusher Jan 09
well I unpugged the EGR sensor and the CEL came on but I expected that. But the good news is so far today while driving around the car never did stutter when it was in idle. So everyone has been telling me that how the EGR valve never fails so I never thought it was but it just may be.
Im going to look at it closer tmr and d/c the vacuum line and plug it and see how it runs for a day or two. One thing I noticed is the car had abit more pickup and power, and I was told that I might get better mpg with it off...call me crazy but then if we only get positive things from disconnecting the EGR crap...why have it on?
2000 Cougar V6
A Landry list of repairs...