I've got an issue that sound some what related but it still has me confused. I have 1996 Legacy Outback with the 2.5l that I just bought two weeks ago, it had the classic "dead spot" in the tps behavior (nothing changes with the engine behavior with certain pedal positions) easy fix right? it had 5 codes present: TPS fault, MAF fault, EGR solinoid fault, upstream O2 and Downstream O2. I thought the easiest thing to fix was the TPS and it might help resolve the others. new tps and down the road we go... not!!! new tps and it ran pretty good til I cleared the codes to see which coeds would come back...and weird behavior here we come. while tring to drive at a constant 35 mph the engine will rev to about 3000 then cut out entirely and catch again about 1500-2000 and then repeat. it retained the TPS, up and down stream Codes and the EGR. I looked and somebody in the history of the Car had removed the EGR sulinoid and plugged all the vac lines to the EGR system, but I didn't think that the EGR would effect it that badly. I put the old TPS back in and it drove fairly decently, switched it out with the new one again and it went bonkers again. why would it be driveable with a bad tps and not with the new one? is there something else Im not seeing/understanding with the ECU system?