My truck is a 97 2500 12valve 2wd with 274,000 miles. At this point it still doesn't know what the inside of a shop looks like, except tranny replaced at 110,000 miles. My issue is that more and more frequently it seems to shift back and forth between gears around 20 and 30 mph then again between 40 and 50 mph. If I accelerate steady and firm such as getting on to the freeway this doesn't happen it shifts fine then. Besides the TPS what else could be happening?

 

That's a really tough one to answer with just one item needed...We replaced more transducers and gov. pressure regulators for this than any thing else . Will overpriced because at a dealer that cost about $700.00.
...I've forgotten which battery cable has the connection junction in it ..that connection can be cut out and soldier back together ..I've seen this fix several ..Our trans tech talked me into putting a alternator on my 2000 ..No it didn't do a thing for mine but I saw it fix one or 2..
....So you see there are several things .. I'd clean my alt connections cheap then fix that connection ...thing I'd go to a trans shop and get the parts for in the trans ..Of coarse you'll change your fluid at this point ..

 

also check your grounds I had 1 were the ground from the bat. (on the right side )to the fender was loose. cleaned and tightened it up problem stopped

 

I have the exact same problem happening to my truck. any luck on fixing it?

 

As a matter of fact, I had the fluid and filter changed and the problem went away. However, the same day I had an old recall done that had to do with the throttle cable so 1 of those did the trick. Good Luck

 

Well it wasn't that throttle cable recall I think that just turned over a washer and retorgued the bolt.. But I bet you problem returns after a while .. I don't think either of those is going to fix it.. SORRY..