I drive a 2003 G35 coupe RWD 6 speed manual.

Anytime, for example, I’m merging onto the highway and I go to accelerate, as soon as I’m in the power band and accelerating hard the car pulls then stops pulling loses power even while I’m maintaining the same pressure on the gas pedal almost as if the car thinks it’s slipping and cuts throttle. The slip light and vdc light DO NOT come on the dash. It does this accelerate, pause, accelerate, pause, accelerate, pause all the way until I’m done hard accelerating and I’m in my cruising gear.

Think of it like you’re riding in a turbo car as soon as you hit full boost, you loose boost, then the turbo spools up against and then you loose boost again and it does this over and over throughout the power band until you’re done accelerating. (I’m not boosted btw this is just an example)

- no VDC or Slip light
- no check engine light
- Throttle body and MAF was cleaned
- replaced the air filter.
- new spark plugs
- new coil packs (didnt do it of this issue, the packs failed so replaced them and the plugs)

Also no my RPMs don’t increase while I’m at a loss of acceleration so it’s not a slipping clutch. My Rod plateau or drop slightly then resume climbing.

My theory, it could be the slight exhaust leak on my Y pipe, past the O2 sensors and cats.

What do y’all think?

 

Had a similar issue in my father's truck and it turned out to be a bad O2 sensor.