Okay...I'm not really sure how to explain this so go easy on me guys. My car has a problem that started as intermitent and is turning into a permanent one. I have an 86 TPI 305 camaro and I noticed about a month ago that there was a slight pop when I left off of the pedal. I wouldn't even call it a backfire cause it wasn't really that loud. That pop has progressed into a bigger problem. Now the car acts as if doesn't know what gear to be in at low and high rpm. It goes from 1st to 4th and vice versa at any time. It always seems to have a chugging feeling. I just put new plugs, wires, cap and rotor. The engine seems to idle all right but once its going down the road all of the problems start.
I do have to mention that the car was in storage for 6 years until last June. I've changed out the cat and a bunch of sensors that cleared all of the codes that I initially had. There is one code that comes and goes and it is the VSS code(I"m not sure of what # it is right now) Could the VSS be causing my car to act up like this? I didn't think that it would cause these kind of problems but I'm not sure.
I can't take much more of this shotgun trouble shooting method that I have been doing nor can I afford it. I've tried a couple times to get a new VSS but the parts stores here don't want to cooperate with me on getting one. I get a different line of crap every time I go.(even at the dealer!)
Any help would be appreciated!

 

Check and see the the tranny fluid is upto the spec level. I would also drain the pan and change the filter.

 

I changed the filter about two monts ago. I checked the fluid yesterday and had to add less than a half of a quart. That didn't correct the problem though.

 

Sounds like what happened to me... the car "Seemed" to not know if it was in 3rd or 1st and when i pressed the gas harder it only got worse.... I thought nothing of it being the cat converter, because... like you i had just had it changed recently and was getting no error codes from the computer..... turns out that there was still crap left in my pipes from when my old cat converter blew out..... moron didn't clear n e thing out.... sounds like its your problem, but dont hold me to it...

 

After I had the cat changed the car ran great. This problem started about 6 or 8 months after it was replaced. I had new pipe put in from the y back.

But your right, it changes gears at crazy times. When you open it up, it jerks the hell outta your head cause it snapps into a lower gear. At low speeds, the thing chugs like its going to stall out, downshifts for a half a second then back to overdrive.

Frustrating as hell!!!