Nope, not getting any ck. engine light and nothing showed up on the dygnostic either. I tend to agree that it may be a sensor due to the fact that it only happens when the engine is cold leading me to believe it's not of the mecanical nature. I do have the 4.0L. Is this a common problem? Have you ever heard of it happening before? I puzzled why a faulty sensor wouldn't show up on the dygnostic check.