hi all. I'm sure everybody is always in a rush to get answers but this I need answered for my livelihood.the other day I was driving and I suddenly lost power or at least it was very weak power. I look down in my RPM's we're off around 3200and I don't believe it had shift into 4th.at idle it's absolutely fine. I can rev it and its fine while its idling. No codes are showing.

by the way its a 1998, 5.2, 4 wheel drive with a 3" lift. It has 218k on it.

I recently tried to change the TPS, what the aftermarket one I bought was no good. So I put the old one back in and it worked but I have the same problem with loss of power. When I start it up and its cold I can drive about half a mile without a problem. After that it start shifting weird and then shortly thereafter it starts to lose major power.

in the past year just for your information, I've changed the CPS, VSS,water pump, brake lines, front and rear brakes, the brakes were just done actually.

mechanic friend told me he doesn't believe its the transmission. There's been no noise or indication of there being a problem previously. He believes the module or even possibly a bad cat.

again,its shifting at high RPM's into 2nd and 3rd at approximately 2700 RPM's and after about a half a mile it won't go in the 4th.I'm not getting any codes at all. Is it possible it could be the output shaft speed sensor? I'm at a loss but I need a quick answer. I'm sure everybody does hahaha.

thanks in advance, I look forward to hearing some of your ideas.

 

I forgot to mention that over the past week, while driving on the highway it had a quick hesitation and then stopped right away and it was fine. It happened twice and twice while idling. Not sure if that helps.