I want to make sure that I am on the right track in diagnosing a CEL that I have received intermittently. Here is the scenario.[LIST]
November

 

Well, the first two should be easy to check...did you?

Your other suggestions sound reasonable but you'll need spares to test your theory.

 

Not yet, no time till this weekend to work on the car.

 

I would pick option #2 as the most likely cause. Is the controller wired with a PnP harness or spliced into the factory harness?

The displacement type splices/Scotch locks that come with the Vortech kit are quite famous for providing intermittent connections.

 

I spliced the wires. I will check there first.

Is adding a plug 'n play harness easy to do?

 

It much easier to make the connetions to the PnP harness when it is on a table versus laying under the dash.