Here is some things that were done to correct this already......could this have any affect on the problems?
The first thing they did was torque the plugs to spec (since Iapparently didn't tighten them down enough). Then they changed thebattery and battery cables because the excessive corrosion causedcurrent to run across the battery terminals. Then they replaced the Idle Air Control Valve (IACV) because the oldone didn't open or close. This is a small part but cost me $458 pluslabor, taxes, and shipping. They also did a compression test - all 4 cylinders checked out ok. A week prior to taking the car to the shop, I changed the plugs andair filter. I also replaced the front and rear catalytic converters -$600 for the part. At the back end of the rear cat is a tapered donutstyle gasket. The parts store gave me the wrong one so i had to reusethe old one. I wonder if this is part of the problem. The cat alsocontains two O2 sensors that I'll have to get them to check.
yes it runs rough and that is when we checked for error codes.....it showed all 4 cylinder misfire codes and The last one is the fuel trim malfunction (A/F too rich).
thank you, XXXXX XXXXX helps.