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View Full Version : Tracing a Misfire...



ssikpiyelnats
06-08-2012, 05:37 PM
Ok, so here's some background:

I just purchased my Marauder on Monday. It's previously had all four CATS removed. There's no check engine light on, however, the downstream O2 sensors are missing (the connector plugs are just hanging there). Upon driving the car the way it was intended, I found a misfire under heavy load in 2nd Gear. Again, no CEL. I replaced all the plugs with Motorcraft OEM style plugs, and one bad coil.

Now, if you've read my other thread, I also changed the trans fluid and filter, the diff fluid and gasket, serpentine belt, and fuel filter.

After test driving it, I'm still getting a slight misfire under heavy load. Now, we tried to plug our ScanTool in, and get a misfire reading, but there's no communication. I think whoever owned the car before did some aftermarket wiring to bypass a CEL.

I was thinking of replacing the other coils (they come with new boots), but that's going to get expensive. Any suggestions?

RF Overlord
06-08-2012, 06:06 PM
Before you start throwing parts at the issue, you really should confirm whether the MIL is working correctly, and also get a code scanner to work. Check for +12V on pin 16 of the DLC.

SpartaPerformance
06-08-2012, 06:50 PM
There has to be some issue if there is no communication. I'm not sure with about Panther cars but there is a fuse on most Fords that have an affect on the OBDII diagnostic port, check for blown fuses.