Hi everyone, New guy here
A little background 1st
I have a 1996 2.5l v6 with 150K on the clock
My fault codes are PO7033 and PO7034 which just tells me it wont upshift into 3rd and 4th.

I bought the car as a basket case, the car wouldnt start so i started checking all basic stuff, spark, air,..... fuel, Ha! found it Fuel delivery problem R n R'ed the fuel pump and filter and and we have success! The car runs really good. when driving, It wont shift into third. I check the Trans fluid levels and they were so low that it almost unreadable, (hence the fault codes?) but there was/is fluid in the tranny just at the low end of the stick, So I filled it up, used a bottle of Lucas oil and Castrol +4 drove the car around the block and it smoothed right out but still wont upshift into 3rd or 4th(obviously) it upshifts but wont "catch" or "drop" into 3rd its like it gets stuck in nuetral then "drops" back into 2nd is the tranny already toast? Or could it be the Shift Module failing?
Is there a running theme with these transmissions that im not finding? what is the most common failure? and is there a way for a DYI're to fix it ?
Because well know tranmissions are NOT cheap......

 

A couple of thoughts. There might be more codes in there that can be read by a better scanner. If you have any reservations about the scanner used to get those codes, consider consulting someone with a better machine. Given the price of transmission repair, it's probably a good idea to spend some money on diagnostics including the best available electronic diagnosis plus some hydraulic diagnosis as well.
Also, if your fluid was that low, it was probably in pretty bad shape. Merely adding to it wouldn't get rid of the bad stuff. A good flush might be in order. Again, it will probably cost a hundred bucks but if it saves $1500 in repairs....
Make sure you put in only the proper fluid. Don't use ATF 4 if ATF 3 is what the trans was designed to use and vice-versa.

 

Here's another possibility you should explore:

Chrysler automatic transmission repair: solenoid pack rebuilding

If you don't want to rebuild the solenoid pack, you can buy one for under $100 and just replace it. The article covers removal and replacement.