1st indication was engine hesitation. Sometimes battery light would flash on and off.Computer 1st indicated code P0301 (#1 misfire). A few days later it threw a P0300 (Random/Multiple cylinder misfire detected) and P0303 (#3 misfire) and P0404 (#4 misfire). Alternator was cranking out 14 plus volts even during misfire and battery was 12.6 volts with engine off. Tried swapping ignition coils to no avail. Pulled Fuel injectors for inspection and they were clean. I thought about 02 sensors but moved on. I thought maybe a fuel pump / filter issue; pulled out rear seat and cover to fuel tank in order to tap on pump during misfire - no impact. Finally it dawned on me to inspect the MAP (Manifold Air Pressure) sensor for oil and dirt. Pulled it out and it was a little bit oily dirty. Cleaned with Mass airflow sensor cleaner and toothbrush and lightly blew it out with compressed air, reinstalled and so far no issues.
UPDATE: Well that didn't last long. Other than O2 sensors, not sure what's left to look into.

 

It is odd that it affected only certain cyls. Lets hope your luck holds out.

 

Best thing to do, is pull one coil. Have engine running and see if by chance the spark is coming from the side of the boot, instead of the bottom like it should..

 

Thank you. I don't believe 3 of 4 coils would be affected at same time. Anyway, even though I cleaned MAP sensor I disconnected it and drove for 8 miles with no misfires then reconnected to be on safe side. Part is on order from Rock Auto. Will keep everyone posted.

 

Strange how when it's unplugged the car works fine. Maybe it's wiring? I had a similar issue with a 91 Eclipse and it turned out to be the computer.
Can a dealer test the computer?

 

The systems are designed to allow the vehicle to function and get to a service facility for needed repairs. When you disconnect some components , the computer switches to a temporary profile and substitutes values to allow travel for repairs, but will not do this for any extended period of time.

What is generally done is to check the computer memory for any stored codes to provide some direction to diagnose and make necessary repairs.
Codes do NOT always mean a component is malfunctioning, it could be poor electrical connection(s), poor power or ground conditions too.

 

So for kicks and grins I pulled the #3 coil while the car was running. It did not short to ground through the insulation; when I put a lead in the coil and near grounded the it to the car the spark was weak to non existent. I ordered an entire set. There maybe a couple of issues happening simultaneously. Will keep this thread posted.

 

If you remove the normal path to ground for the spark coming from the coil, you risk destroying the ign module,, NOT RECOMMENDED.

That spark has to go somewhere and if it can't, it finds a way through the ign module. If you are checking that way for one problem,you risk producing a second problem without knowing it.

 

Hank,
I am surprised you didn't respond to doubledragon5's recommendation that I do this.

 

Sorry about that, work kinda spoils your whole day !