!993 MGM intermittent check engine light

[Donal]

Recently acquired this car. Has about 71,000 miles on it. It's got the 4.6 motor. Replaced the starter and did an oil, filter change on it, and replaced the stock stereo with a pioneer unit. The more I drive this car , the better I like it. Have put prolly 2-3000 miles on it. A few days ago the CEL came on for a few seconds, then went off. Everything seemed fine, running wise, and temp gauge was ok. Couple days later, it did it again a couple times. Tonight it came on 3-4 times. Usually has come on when I'm cruising down the road. Haven't noticed any running problems, except tonight, at on point, there was some jerkiness when I accelerated after slowing down a bit. Anybody got any ideas. I drive 50 miles one way to work, and would hate to break down to or from.

Don.

[79lincolnlover]

My guess is that your GM needs a tune-up. Also a good idea to clean out the EGR passages. After this work is done, you should notice improved performance

[sly]

yeah... my 93 vic needed the EGR channels cleaned at 100K and again at 160K ish... odometer stopped working at 130K and I didn't fix it for an estimated 40-50K miles. pretty easy job to do with only a torque wrench needed for putting the throttle body elbow and EGR valve back on. I never had any issues with running though. You'll want to pull the memory codes to see what the error was. When I had the EGR channel problem, I got egr low flow codes. If it's a misfire code... you probably need plugs/wires.

http://www.grandmarq.net/vb/showthread.php?41370-EGR-ports-cleaning-Procedure-with-Video

Here's pics of the crud that was built up in my EGR channel (Before and after shots)
Nasty:


Clean:

[Donal]

Wow! That thing looked to be plumb full!

Don.

[86VickyLX]

yeah, had same issue with my mom's 94. Checked the codes it was for EGR. 331 iirc. I cleaned that passage and the codes went away!

[Donal]

That'll be my next project for sure!

Don.