I'm having an issue with my Grand Prix that seems a bit unusual. For the past month or two, after driving to warm up the car a bit, it "hesitates" at extremely low speeds (less than 10km/h) when trying to accelerate. A more specific example is if I'm in heavy stop-and-go traffic and I brake/coast to almost a standstill, wait a few moments and then try to accelerate, it hesitates for a second then "clunks"/lurches forward once it gets enough gas. It almost feels like it's going to stall, but it doesn't (or hasn't yet...). Strangely, this does not happen when accelerating from a complete stop, only when accelerating from extremely low speeds. If I accelerate very gently, the symptom disappears or is significantly lessened. It gets worse after driving on the highway for a while.
I replaced the camshaft position sensor less than a year ago, so it's not that. It did have a code for a bad O2 sensor (bank 1 sensor 2) which was replaced yesterday, that did not help either. There are no other codes in memory. Was a long shot, but the air filter was replaced a few weeks ago as well to no avail. I also checked the MAF sensor which looks clean - however, the mesh on it is crumpled in a few spots, but it's been like that since I bought the car 5 years ago. Someone did suggest to me it could be a mechanical rather than engine issue, but the fact that it gets worse the longer the drive makes me doubt that.
Anyone have any ideas for what to check next?
