Newbie here, needs help concerning lockup sensor

I was told, more than likely, the reason I've been having car troubles is a bad 'lockup' or 'overdrive' sensor.

I know absolutely NOTHING about cars even though my dad is a well experienced mechanic (he lives 1200 miles away so he's no use to me)

Here is my problem:
My car starts up perfectly, but after driving it for a few miles, when slowing towards a stop I feel it jerking (the tachometer jumps from 500rpm - 1500 rpm) and sometimes it will stall out. Then, I try to start it back up, it starts up just fine but when put into a driving gear such as Drive or Reverse, it will immediately stall out. I let it sit for about a half hour, started it up, and drove on my way again without problems. It has happened on more than one occasion so now I only drive it to and from work. Also, when I get up to around 45 mph, it feels like the car kicks into a higher gear (like if you were to try to go from a stop in a manual starting in third gear, that's how it feels sometimes at the right speeds).

It's an 88 Cavalier Z24 with a 2.8 engine (automatic transmission)

The thing is, I can't find anything about a lockup or overdrive sensor... I did some searching here and think they're referring to it as a torque somethin or another, which of these two parts match what I've been describing?

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=GPS&mfrpartnumber=7793539&parttype=280&ptset=A
or
http://www.partsamerica.com/ProductDetail.aspx?mfrcode=GPS&mfrpartnumber=CSS7&parttype=762&ptset=A
??

And the real reason behind this is I am told if I unplug it, it should run just fine, but I have no clue where it is and what I need to unplug it. I am so mechanically challenged its not funny, but also too broke to take it to a shop. So if somebody would kindly tell me exactly where and how to unplug this I would be eternally grateful.

Only unplug it on a 3 speed automatic transmission, which is probably what yours is. The location of the sensor, looking in from the hood, should be somewhere on your right, sticking right out the front of the transmission. My dad and I have unplugged several like this and never had any further problems.
I just heard its a bad idea to do on the 4 speed auto (overdrive) trannys, I don't know.

Ditto.

I heard there are like 3 sensors in that area, how will I know which one to unplug?

I've only ever seen one sticking out of the tranny in that area. I wish I could show you where it was. :p

Sounds like you all have had the same problem that I have had - it is the lock out Solenoid. Costs 250 in our area to replace. If you look under the car on the transmission there is a plug with a couple of wires coming out of it. Mine on a 93 was right up in the front.
on mine - as you are facing the engine - looking down behind the radiator - to the right of the engine - you see the trans - on the front - towards the radiator - there is a plug on the transmission - it has a little clip you have to undo and then just unplug it.
It will run fine - mine has for several years. What happens is that when your are on the highway it doesn't lock up and drop your rpms down about 500 or so.
That's the quick fix and unless you are doing lots of hwy driving you will probably never know the difference.
It won't hurt anything - being unplugged - keeps you from stalling out at intersections!
jdw

I have a 1996 cavalier and i took it to autozone to get a free check engine light diagnosis. They told me it was that "lock-up" something or another in the transmission.

This is a good thread because this leads me to my next problem!

I have a 1996 Cavalier like I said above and one day i noticed my transmission acting weird from trying to shift from 1st to 2nd and sooner ot later it just totally went out

Now i am driving around my car with no 2nd gear. Do i need a new transmission? or is it like a link or something in the actual transmission its self? right now it just revs up to about 5000 rpm and then automaticly changed to OD or 3rd gear. Its not to bad to drive but it gets old...

oh yeah and one more thing.

KJRich, where did you get those cool things for your rear windows, i have been looking everywhere for those and i can't find them anywhere in Minnesota!