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98 GP GT with a PO442 code and light on.

Fritcr

Fritcr

New member
My "new to me" Grand Prix has a SES light on most of the time. Sometime it goes off and I have a code reader and have cleared it a couple of times but it comes back on. Any ideas what this might be. It says Evap Emissions Control Small leak or something like that. I was going to pickup a new gas cap at lunch today but I doubt that is what's wrong. I did some searches on the web and got some hits for other gm cars and things were mentioned like canistier leak and vac leak. I'll try to check out as much of that as I can.
Thanks so much for everyone's help. I can do most stuff myself on my car but sometimes need a little guidence!
Rob:th_laugh-lol3:
 


Generally speaking, when that code pops up, the gas cap is the first thing to look at. If you replace it with a quality cap and the code remains, then its probably going to be elsewhere. A possible way to tell if it is the cap is to note whether or not the code comes on after such times as filling up with gas.

It could be a vac leak I suppose but Id still start with the gas cap.
 
I would start with the gas cap as well. And when replacing it, make sure that your filler neck is in good condition. One car I had, the gas cap was brand new. But the filler neck was rusted and not sealing well, giving me this code. Replaced the filler neck with a good one from the yard, and all was well.

But like scotty said, could be a vacuum leak as well. But I would start with the gas cap.
 
just an FYI... if your car has the tethered cap, and you want to keep that, you have to go back to the dealer... who'da thunk that GM had a patent on a gas cap tether???
 


Thanks guys, I have been traveling for my job and just got back. I have a rolled 98 Montana so I will take the cap off of it tonight and see if that helps. I would think it would be the same.
Rob
 
my gp has the po442 code and is leaking coolant very slowly from the right side of my intake manifold by the throttle body. i am already planning on replacing the gasket and manifold but just wondering if this could be why the codes on. ive hear the code could be be a "vacuum leak at engine". would this be considered a "vacuum leak"?
 
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