ALOT of codes/I have no idea where to start PLEASE HELP!!!

:banghead: :crying: I have a 95 Jimmy, and it has been running terrible for a while now. We did a complete tune-up in August and then the truck would run ok until it got up to proper temp, now it isn't running good at anytime. In park it seems to run better, but not right, still rough. It's also running really rich, I can smell it pretty strong while running and looking under the hood.

I took it to O riley's today and there were 4 codes,
1. Multiple Misfire
2. Throttle Position Sensor
3. Transmission shifting
4. 01100 and the guy at Oriley's didn't know what that was.

But he suggested I change the TPS, and I did with no change!!
I don't want to keep throwing money out for no reason.
Before when it would start running rough like this the egr valve was clogged, but I took it off and cleaned it then put the screened gasket, and no change.

Any suggestions would be appreciated???
I would like to get it fixed before winter.

One other thing is can I reset the codes by unhooking the negative cable or does it have to be the positive cable. The only reason I ask is my positive cable seems to be stuck, so I've been taking the negative off to try to clear codes, I'm just not sure if it's the same. Sorry if this sounds stupid, but it's been a while since I've been in automotive.

ALWAYS UNHOOK THE NEG CABEL FIRST AND HOOK IT UP LAST.
If it still has missfire codes after code clear work on that part.
Check for dead miss or a ramdom missfire.
How is cap and rotor and plugs and wires?
Ac delco plugs?
Fuel pressure?

I have done alot to this truck lately trying to figure this out, so I think that's why it had so many codes, anyway I finally got the positive cable off also and the codes cleared and the Jimmy is back to normal for now. I love this website. I'm sooo glad I found this. I'm sure I'll need you all in the future but hopefully not soon!!!:lol2:

I have done alot to this truck lately trying to figure this out, so I think that's why it had so many codes, anyway I finally got the positive cable off also and the codes cleared and the Jimmy is back to normal for now. I love this website. I'm sooo glad I found this. I'm sure I'll need you all in the future but hopefully not soon!!!:lol2:

You are welcome and thanks for posting back how it went,