96 Legacy 2.2L: When driving on an uphill road, the engine starts vibrating and the check engine light comes on. If I ease off on the accelerator for a while, it gets OK. If I press down on the accelerator and go into overdrive, it also gets OK. The first time the diagnostics showed knock sensor problem and I replaced that. Now diagnostics show cyl 3 misfire and cyl 4 misfire. I have replaced spark plugs and ignition wires. Since the problem occurs climbing/accelerating uphill, I replaced the fuel pump, fuel filter and added injector cleaner several times to the gas tank. The problem still exists. Any idea what I should look at next?
Thanks.