1998 explorer 4.0 sohc

Ignition system includes plugs, wires and coils n the secondary side.... ICM and PCM on the primary side. My first inclination would be to fuel system faults for what you describe but, there's not much info to go on..... Miles on the car, how long since last tune/air filter/fuel fiilter and so on? Is the CEL on, even if it's not, are there any codes? Where are the fuel trims sitting? Are there any other running symptoms besides bad mileage?

Hey Jim,It was remanufactured about 1000 miles ago, it has run rough since then.I had one side or the catalytic converter replaced, think the otger side needs replacing also. At the shpo where replaced the cat converter, they scanned it and showed mass air flow sensor. I f replaced it, and then it showed codes oxegine sensors 1 side to rich the other side to lean. Had sensors replaced when they redid motor.I don't know if wires or coil have ever been replaced. It had 129000 miles when motor in was replaced. The hydrolic tensoners were bad. But it was running a little like this before motor was replaced. Now it hesitates, and runs rough at idle, you have to really push on gas to get it going. any help would be appreciated.

If this stuff has surfaced since the mtor replacement, I would first go over any and all connections between motor and chassis. It's amazing what a bad ground or improperly assigned vacuum line can do. If your shop is struggling with their diagnosis, it may be time to find a different shop....