Mine does the exact same thing, Different vehicle but same problem.
I have replaced tons of sensors and checked a number of systems ie. oil pressure. spark ect.
No one knows the reason why this demon is doing what it is doing. It has even gotten to the point of stalling and backfiring. Only in the Mornings though. Or when competly cold. My next check is the PCM or injectors and injector electrical harnesses. Make sure you have no Vacuum leaks first.
Good luck let us know how you make out..
