Thread: 04 Grand Prix Stuttering on acceleration

Had a very similar problem to this and it kept getting worse and worse. Turns out it was a clogged cat.

Update: I checked the CAT's on it and they seem to be working in good order. Exhaust is hot - bought a laser temp gauge and the front is pushing 550+ degrees at around 2k rpms, the rear is pushing about 400 on the in and on the outlet. I am under the impression that it should be at least a little hotter on the outlet, but that if the CAT is bad the temperature difference is usually about a hundred degrees lower on the outlet.