[glennf1]

MAF itself could be bad or the wiring from it going to the computer. My only other guess would be a forward O2 sensor. If your cat was bad the rear O2 would catch it and that's only for emissions anyway, the forward O2 is for Air/Fuel. The codes are your friend.. it would not have thrown a MAF sensor code unless it was out of range or not receiving feedback from it. Unplug your MAF sensor and drive it. If there is no difference I would replace it.