I have an 01 turbo with 25k and afew mods on it. It runs hard in 1st and 2nd gear when stepping on it but in 3rd gear toward the higher revs it sputters a few times. Mods include k-24 turbos, fabspeed header/exhaust, evo cold air intake, billet diverter valve and giac ecu.I dont seem to have a problem with the check engine light so im thinking the o2 sensors and maf are fine. any ideas would be appreciated.

 

whats it like in the remaining gears?

 

No problems, I think because of the longer times it takes to rev up in the higher gears. The problem only comes when I accelerate hard

 

hmm. Sounds a bit like fuel starvation? Has the car's power been upgraded significantly?

 

Classic symptoms of bad spark plugs. By 30k miles, the plugs are done, especially with aftermarket work.

It is a fairly decent sized job, but very straight forward. I think book is about 5 hours (my record is 42 minutes ). Involves pulling the rear bumper and intercoolers to access the plugs.