Thread: 04 GTP Sputters When Under Full Throttle

Hello,

I just bought an 04 GTP and of course 3 days later it now sputters VERY badly when pushed at full throttle, which I've done less than 10 times, but the 6 or so yesterday and today have got progressively worse. Seemingly zero problem at about 40% throttle and under, but if you floor it, it bogs down almost immediately. I was thinking fuel filter or cat, but since I'm new to these, I thought I'd ask a community of owners first! Thanks for your help and I hope to help others here one day once I get to know this car better.

Before you go out buying parts, inspect your wires first. If you have a scanner you can figure out if it's one cylinder misfiring or multiple. If you can scan for which cylinder is missing you can try swapping wires (ex: move the "6" wire to "4" on both the plug and coil) and seeing if it moves.

Like Death Punch said, it's almost always plugs and/or wires.

Thank you for the replies, lots of good info there. I was hoping this was a common issue, has no one experienced this before?

It was my wires. One time a wire got sliced open somehow, and another time one of the boots popped off the plug.

THANK YOU!! Keep them coming if this ever happened to you. Did you guys take your cars to a shop to figure out what it was, or did you look part by part yourself??

As I said in the OP, I just got this car. I don't have service records, but it does have red plug wires, so someone changed them. I guess the thing that's making me wonder is that when I bought the car, I could floor it and it'd go like a bat out of hell. However, 3 days later, it would no longer go. Only thing I did was put in fuel system cleaner. Could it have gunked up my injectors?