grand prix gtp surging

[kawasakidrivinghick]

I been having some problems with my 2001 grand prix gtp, i would really buck and spit and sputter while on cruiseing speeds so i changed plug and wire for number 4 bc thats what the code was, it runs better but now at idle is surges and runs ruff. coming up to speed on highway if i hold it around 1500 to 200o rpm the rpm will surge with a load. when it was raining the other morning heading to work it felt like it was slipping. the rpm wouldnt move but i would feel like the trans was slipping i come home no rain and nothen anyone have a idea for me to start with fuel filter was just changed.plugs and wires around 50000 miles ago

[FordMan77]

Sounds like you may have a vacuum leak. Check all the lines for leaks, and check the T under the S/C snout for cracks as that is common.

[kawasakidrivinghick]

ok thanks what about the slipping feeling seems to do it when its raining hard

[Elite6]

Check codes or MAF?

[kawasakidrivinghick]

check engline light isnt on and i never had a code for that