part throttle violent jerking and hesitations
In fifth gear on the highway, driving 75 miles per hour, at more than 30% throttle, my car has violent jerking and hesitations, but no codes. It does it on the stock tune, as well as on cobb stage 1. Plugs, injectors, coil packs, and turbos were replaced 5k miles ago. What should I do to troubleshoot? I've already ordered 6 new coils packs and 6 new plugs, but I'm afraid that that's not going to help. Could it be hpfp(and if so how do I get the dealer to replace it without codes?) The jerking is very pronounced and obvious even to the passengers in the car. I suspect it's misfire, but for some reason there are no codes. It does the same things in other gears, but it's most obvious on the highway in fifth, or sixth. I use the accessport to check for codes, and there are none. Please help. The car has 50600 miles, and is out of warranty.