Transmission Issues

[dz09x]

So about a month ago when I was on the high way, At around 60mph the car started to act weird. The rpm gauge was fluctuating back and forth and the car itself was shaking and kind of jumpy, when I lowered my speed, it worked fine. On monday, however, The same thing happened at around 10mph. It seems as if the car wants to shift gears but it can't and eventually the car stalls out. Start it up, Idles perfect, put it in gear, drives around 30 feet and the same problem happens, the car acts as if it wants to shift gears but it can't. Any idea what it could be and what the course of action to fix this? am I looking at a faulty sensor or a tranny rebuild?

[SuperHbody]

Is the check engine light on? I'd doubt it as there is "hidden" transmission codes but it's worth asking. First place I'd start is checking the transmission fluid and make sure that is where it should be.

[dz09x]

No codes. Fluid is fine both in color and level.

[SuperHbody]

Could be the pressure control solenoid, I know that is one fail point of this transmission. Usually it'll leave a hidden code that only a Tech2 can read.

[nos4blood70]

How's the power? Sounds like a clogged cat.

[spoiledred94]

Probably is a clogged cat from what I've read about it. Also maybe the ignition system, bad plug or coil or wire

[dz09x]

Coils and wires are solid. No issues there. Clogged Cat is a maybe. Will say that the car in recent months has had a feel as if it were sort of dragging a bit, but if i accelerated hard it would go like no other. It might be the Cat, but it seems more like the transmission. Thoughts?

[SuperHbody]

Would have to do a back pressure test or watch the O2 sensor readings for the cat although that can be inconclusive.

[nos4blood70]

If you tap on the cat with a screw driver or something and it rattles, that means it's bad. Also, if you come back from a drive in the evening or at night and the cat has a red glow, that's another give away.