Hesitation shifting between 3rd and 4th

[havok94]

Ok, I got a 2001 Grand Am SE, 2.4 L engine. The car only has 42,000 miles on it. My problem is this-- when I am driving down the street and I hit about 42-45 mph the car starts to shudder like it isn't shifting into 4th gear(it's an automatic). I thought maybe it was a plugged fuel filter so I changed that, I also pulled the plugs to check them and figured I might as well replace them while I had them out. Niether of the changes helped. The reason I changed the plugs and fuel filter is because my wife went and put some cheap gas in it. I have tried running 93 octane gas in it to possibly clean out the system, but that isn't helping either. I am on the third tank-full of 93 octane gas(BP gas). Could it be the transmissing fluid and filter need changed? Or possibly the cat converter? I'm really in a bind and need some help.

[Ridenour]

maybe coil packs, or could be a clogged cat converter

[Slade901]

If your vehicle has a MAF (Mass Air Flow) sensor, clean it first and test the vehicle.

[Jeremy366]

I am having the same problem with the same car at 58k. I also notice it on the highway at 60 mph trying to accellerate and having the car hesitate.

[Morpheus5057]

I'm having the exact same problem. Girlfriend drove my car with sandals on, and she said it felt like the gas petal was sticky just a little bit. I put WD40 on the petal arm, and it stuttered less, but came back. Everyone else that drives my car says nothings wrong and they cant feel it... but i know it's there. How does one "unclog" their cat converter? or change the coil packs.... And, how would i know if i had MAF? i have a 2001 SE 2.4L with only 26k miles. Please AIM me or [email protected]

[punk100]

change your air filter and see if the problem goes away mine did....its a $6 fix.