2001 Pontiac Grand Prix Check Engine Light

I recently replaced my EGR valve because the check engine light code came up on my car, along with that I also had to replace my catalytic convertor, from what the mechanic I went to said, is that the bad EGR valve caused the catalytic converter to clog, I don’t know how true this is because I recently talked to someone that said that a bad EGR valve could not cause a blockage in the catalytic convertor and that it must have been from a recall that was placed on the car when it was recently bought(many years ago).

Besides the fact, when I replaced the EGR valve and the catalytic converter in my car it ran smoothly afterwards. I am in the military and I just recently had to park my car for 3 months while being out to sea. No later than 2 days after returning home, my service engine soon light was back on. I had my car hooked up to a computer and it was the EGR valve again.

I am wondering if it is a intake issue or an electrical problem because I have checked and lubricated the EGR valve pintle which makes it open and close and it moves freely so that is not the issue.

Answer: There are many different things that can cause the EGR system to set a code. Basically what the system does is recirculate exhaust gases, through a metered system (the EGR valve) back into the intake to be re-used by the engine, thus cutting down on emissions. The vehicle’s computer monitors this system and commands how much the valve moves and when it moves. If there is a difference in the position the computer is asking for, and the actual position of the pintle, that will set a trouble code. If there is more or less exhaust gas flow than the computer is looking for, that will also set a code. And of course if there is an electrical problem with the valve, or the wiring to it, that will set a trouble code as well.

Since you haven’t exactly said which code your car set, I’ll just have to assume it’s due to one of the previously mentioned items. On a separate note, it is odd to find a catalytic converter that has been taken out by a faulty EGR valve, but not knowing your exact situation, I can’t say whether you really needed one or not. You may want to check with your local GM dealership to see if there any updates to the operating system of your vehicle’s computer that correct any EGR problems.

Being a 2001 model, and if you’ve infrequently seen a dealer for repairs, there could be many updates that fix known problems, and an EGR problem could very well be one of them. Something to look into, for sure. Otherwise, you might want to make sure the wiring and connector look ok and fit snugly. If you used an aftermarket EGR when it was replaced, I’d highly recommend putting a GM part on there. Hope this helps!

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