2001 4.2L V6 134,000 miles
Today, while slowing I noticed a hard downshift. Then wouldn't shift into second.....then it started shifting in each gear (not sure about overdrive) very late with rpms higher than normal. It is also idling high? In fact, when I let off accelerator, it seems to remain at the same speed.....as if the gas pedal is slightly pushed. My check engine light has been on for a while due to a evap code (leaking gas cap) and I have not yet been able to take to run codes. Runs great and no other problems. Please tell me this is some sensor or something and not a fried tranny. Thanks much

 

Is your speedometer working correctly? The VSS on these trucks will go bad sometimes, which will cause the trans to downshift or not upshift, hold a gear, erratic up-down shifting etc. I ask about the speedometer, because this is what that part controls. All your transmission shifts are done by this sensors signal. Thought I'd throw that out there for you to check. The VSS will set a code, so by all means, get them read, before you go throwing money and items at the truck. The OBD II port is our friend. Use it. lol

(VSS is vehicle speed sensor)