Rough Idle and Check Engine Light Due to Sruck Open EGR Valve on GMC Jimmy

4.3L V6 multi-port FI only
The exhaust gas recirculation valve (EGR) may stick open causing a rough idle and the Check Engine Light to illuminate. Our technicians tell us that a piece of carbon may become stuck in the valve causing this problem. Cleaning the valve will usually correct this condition, in some rare cases the valve will need to be replaced.

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Average mileage: 210,000 (170,000–250,000)
3 model years affected: 1992, 1993, 1994
6 people reported this problem
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problem details
1994 GMC Jimmy 250,000 mi,
Egr valve does get carbon stuck in it. Save your money 9 out 10 times its carbon build up. Especially for all who have the vortec 4.3 w code. Buy a egr gasket that has a screen in it. That will fix your problem. Gm had yet another poor design with plastic intake that traps carbon when the vehicle is hot. Then as it cools the carbon get hard. When you start vehicle up after it cools, little pieces of carbon break off and get trapped in the egr. Three sensors are used to calibrate engine performance. Tps, egr, iat. Throttle position sensor egr valve and intake air temp. One fault of the three will effect this motor greatly.
rough idle, car stalls at idle. Just about to take it apart to clean. I had the same problem two years ago, and took my car to a shop to get it replaced. This time I'll try to save $$ and do it myself.