I've got a 96 SE and I can't feel it missing while I'm driving it but when it's in park and I rev the throttle it starts missing at 4000. Recently I've had the plugs, wires and fuel filter changed. The CEL light has been on for several weeks but it was doing the same thing before that. I had the codes read yesterday at a transmission shop and they said it was the downstream exhaust and was running lean. I guess that would be the cats or O2 sensors? Fuel pump maybe? Anyway, should I replace the sensors and see if this improves performance? The cats have a real strong sulphur smell if I drive it hard.

TIA
Mark Stenger