The O2 sensors are the original sensors, I have not done any repairs exept to clear the codes. I agree if it is not broke, don't fix it. I will wait and see what happens. I was just looking for an explanation, but I may never figure out what happend unless the code comes back.

Thanks for all the opinions, this forum is very helpful.

I also do not believe the 2.7L is a crap engine, it just needs to be maintained and will give good service.

Jim