My 03 360 is having issues and I am scratching my head. When I am driving anywhere between 45 to 70 mph, I can easily press the accelerator and the engine for lack of a better phrase seems to vibrate almost as if it is struggling or if maybe the butterfly’s on the throttle body are not opening fast enough, makes it almost sound like a Diesel engine, but again only if I lightly accelerate at the speeds I mentioned and only for about 5 to 10 seconds. Then it immediately goes away and runs nice and smooth. If I put my foot in the accelerator it has plenty of power and no vibration it runs like it is supposed to. NO CODES AT ALL!! That is where I am getting lost. New plugs, wires cap and rotor about 6 months ago, along with TPS and IAC. I did however recently change out the MAP sensor and Crankshaft Position Sensor and my problem seems to have went away and now has returned. I am hesitant to jump and say that I need to replace either one of them again as I just did that about a month ago. Has anybody had anything like this ever happen? I just hate to throw parts at it but hoping I am missing something that someone else may have thought of.

I had the TB off about 6 months ago but didn’t see any oil, doesn’t mean it will be that way now. I was thinking about the plenum gasket as well seeing no codes on the engine and in fact was going to pull it off to clean it anyway. As far as the O2 sensors I am assuming they are factory. I bought the truck used so guessing on that.