I have a 96 OBS with the 2.2 and the auto trans, and i have a hesitation problem.

 

at low and part throttle when i try to accelerate the engine gets louder, but dosn't spin faster, but if i mat the throttle she'll accelerate fine, at least fine for an automatic.

 

I've swapped in a new TPS cause i thought it was sticking, but that has not made a difference. I keep hearing fuel filter and O2 sensor, but with good acceleration at high rpm i doubt its the fuel filter, but stranger things have happened.

 

I'm stretching now, but it could also be a clogged Y pipe i guess, but i don't think so.

 

Let me know what you think

It's done this as long as you've owned it?

Yeah, for about 10,000 miles give or take

I was getting a check engine soon light popping on and off for awhile with no ill effect noticeable. finally the engine started the hesitation/dogging thing upon acceleration but was fine when i punched it. So i took it in to the mechanic and for $60 he pluged the ODB in and told me it was a engine knock sensor. Changed it for $81 and now its fine. has the check engine light come on at all? the computer stores the codes and its better to spend the cash on the diagnosis rather than an o2 sensos, tps, fuel filter,etc etc youll go poor trying to get it right.

i replaced the crank, cam and knock sensors a while ago, that was the codes i was getting, that and the upstream O2, but i've been lazy in fixing that one.

If it scoots when you boots, then it's not a plugged exhaust.

 

It's almost certainly gotta be something with either fuel or spark. Have you got MAF or MAP style fuel injection?

Maf

You might wanna try cleaning the MAF wire and verifying the operation (resistance curve) of the IAT sensor, before going further. These two are as important as the O2 sensor for getting the part-throttle fuel mix and spark curve in the happy zone.

 

When you tromp the gas you move a lot of real-time parameters over to a WOT fixed map for the duration of the WOT event.