My Serivce Engine soon light as come on and my engine is running rough. At times the condition will go away which indicates the problem is electrical and that mechanical components are sound. I assumed I had a sensor failing. Most recent symptoms include choppy idle.

Last weekend I noticed that one of my ignition posts (not sure of the official name - this is my first car without a distributor, so this would be the post the spark plug wire connects to on the ignition side of things, not the plug end) is corroded and rusty.

Is there any way to clean or replace just the terminal or do I need to buy a new coil unit as well? Are they sold per coil or is the whole bank replaced? Any ideas as to what causes just one terminal to corrode? I am hoping this is just simply a case of one cylinder not firing consistently. She'* probably due for new plugs and wires too, @ 133k -not sure what previous owner did.

Any suggestions appreciated.
Thanks,
Shawn

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2000 SLE

First up, you should get it scanned for codes, preferably while the check engine light is on. Most auto parts stores will do it for free, or give you the equipment to check it for free.

You will probably end up with a misfire code based on what youre describing, but it could be something else.

As for the coils, you should be able to replace them individually. But I would start with cleaning them, or at least the one that is dirty.

the first thing is to get the codes scanned...there are 100000 different things it can be....as Hoov said go get the car scanned and Write down the code and then report it here....

And the coil post can be cleaned up with some steel wool, then put on some dielectric grease. The problem that goes with it is that the spark plug cable end will be rusty also, and that'* a bit harder to clean. My personal preference is to replace the coil pack, rather than just cleaning it. However, cleaning it should work just fine. New plugs and wires is a good idea.

Also, as the others have said, getting the code will tell us what, if any, other issues you may have.