1995 gmc jimmy nox gas to high on emissions test! Do I have a bad or pluged egr valve! Msgtmorgan
Saturday, January 29th, 2011 AT 3:00 AM
1 Reply
JACOBANDNICKOLAS
MECHANIC
109,700 POSTS
Either one could cause it. If the vehicle hasn't been tuned up for a long time, that would be a good place to start. Also, have the oil changed before the next test if it is due or near due. If a tune up doesn't help, then I would remove the EGR and check to make sure it isn't carboned as well as the intake where it mounts.