catalytic converter and shifting

[40thannPaul]

Who would have thought??

I was having trouble with my 2002 40th anniversary GP shifting. It would wind through first gear up to 5000 rpms and stop pulling and just scream. To make it shift I would have to get off the gas. I was thinking shift modulator or my trans was on it's way out. I had the trans serviced with new fliud and filter but no improvement. I had a code for secondary air pump which did not seem related. My mechanic wondered about the catalytic converter. They disconnected it and test drove it and the problem went away. The converter was blocked and the back pressure was killing the power. To make a long story short, it now shifts great and I think I gained 15-20 HP. It is like a brand new motor.

Happy Holidays to all!

[TheOtherNick]

ok.

[Ahhhs]

I'm having similar problems with my 2001 GP GT Limited Ed.....Mechanic said it was Catalytic converter but I don't trust them now...(reasons not mentioned)...When it is cold out, the car doesn't have any problems except a little lack of HP....when warm, it's a nightmare...could that be the catalytic converter also? I'm changing the fuel filter and plugs tomorrow first....

[40thannPaul]

The thing that tipped my mechanic to the cat was a code from OBDC for a secondary air pump. He said back pressure from the exhaust was restricting flow.

[Bob hand]

hi I am having the same problem with my 2002 . when cold it runs well. when it warms up it hesitates and sputters. I changed the fuel filter, this did not help. I was told it could be the converter. I have not had any check engine lights yet. Did you fix your issue.

I changed the converter today and it solve the problem. It was plugged solid

[macey43]

i had the exact problem with my 2002 haha

[christophero1973]

It's the cat. Warranty issue.