GTP Idles rough for a few minutes, engine vibrates all the time.

I have a 2000 GP GTP, it has 115,000 miles on it. The intake maniford gasket was changed about 2 months ago, it ran fine after that now when the car it's cold it seems to develop a huge miss the engine shakes as it it had a hot cam in it, last about 5 minutes the as the engine warms up it goes away idles a bit rough after but it does not stall also not SES or any codes are stored.

service done on the car last year.
new fuel pump (old was fine but the gas gage did not work)
new intake manifold gasket (upper and lower)
transmission was rebuilt by Aamco a year ago.
new plugs and wires (i have inspected them they are fine)

after the transmission was rebuilt the car developed a vibration and I am trying to get Aamco to fix it. this is not the same as the one above.

check the IAC valve and it's bore in the throttle body for carbon deposits. If that checks out, you could have a bad MAF sensor, as they will also cause these symptoms and will not always trip a CEL.

I will look into that today, I had replaced the MAF sensor about two years ago.

thanks, will report the findings.

I removed the MAP sensor and started the car but it will not stay on, I have to keep my foot on the gas and the RPMs above 1000 to keep it running.

will look at the IAC this weekend.

Did you mean MAP of MAF?

Either way, you cant just remove the MAP or MAF sensor, you will create a large vacuum leak and the car will not run right.

Sorry, I meant to say I unplugged the MAF sensor. I did not REMOVE it, and I will inspect the IAC valve this weekend.

about a year ago I replaced the MAF sensor and I remember running the car with it unplugged, it did not run this time when the harness was removed.