Alright ill be driving along and without letting any pressure of the pedal the truck seems to lose power, meaning MPH and RPM, then it will kick back up and 10 seconds later it will do it again, it started a just happenin at 35 or so but the past 2 day its been doin it on the highway. i dont know if its the other CTS that i havnt replaced, inconsistent fuel pressure, bad injectors, or even the O2 sensor at the beginnin of the Y pipe, i dont even know if these are any of the problems. Another thing is you can smell the exhaust really well, and it will idle normally at a stop light, sometimes it wants to die on me but will kick right back up, so that got me thinkin that it could be that i need another IAC. any ideas or help would be greatly appreciated.

 

IAC is one possibility, as well as a bad O2 or a vacuum leak. Do you have any check engine light codes?

 

No CEL, would the O2 be a problem if i dont have a caytalitic converter?

 

and i have not found any vacuum leaks