contact with during the plenum removal/install. I will hook my NProbe into the system to see if any codes show up, but the coolant temp sensor is new also and I doubt that it would go belly-up all of a sudden. But, stranger things have happened. I'm suspicious of a bad/new IAA or maybe the ECU is crapping out. ECU is the only part that is the age of the car, unless it was swapped out by JWT when I had it chipped in 2004. Good idea about running diagnostics. O2 sensors only have 3000mi or so on them.