Chevrolet Repair: 1997 Chevy S10 2.2 automatic 4cyl 2wd, chevy s10, low oil pressure

Question
My s10 is having problems shifting, when you press the gas petal all the way to the floor the engine revs high but will not shift, like you are in neutral. if you ease the petal about half way or a little less it will go alright but you can barely reach 70

I've replaced the transmission speed sensor, nothing changed
the truck also has low oil pressure around 20 pounds i have no idea if the two are linked some how at all

the problem has stayed the same since I've owned the truck with nothing getting worse at all or better

I'm not sure if it is a cable or a solenoid or what it is
the truck seems to run alright other than the shifting
it starts fine, sounds fine, nothing really wrong at all except whatever is wrong with the transmission
i don't think its actually the transmission since it hasn't gotten worse, when you hold the pedal down while its revving and wont shift it will bog down after a short time

any help would be nice
thank you

Answer
HI MATT,WHAT I THINK YOU ARE SAYING IS THAT THE TRANSMISSION IS SLIPPING !!! RPM'S GO UP AND VERY LITTLE MOVEMENT... THIS IS NOT A CABLE OR SOLENOID PROBLEM..HAVE YOU CHECKED THE FLUID IN THE TRANS YET. IS IT FULL,CK WHEN HOT AND ON FLAT GROUND AND IS IT CLEAN,BRIGHT RED ??? THE ENG OIL PRESSURE HAS NO RELEVANCE AT ALL ON THE TRANS,SORRY. THE BEST CASE IS THE OIL IS LOW. IF SO, FIND AND REPAIR THE LEAK. IF THE OIL IS VERY DIRTY CHANCES ARE THE CLUTCHES ARE BURNED UP.. BUT IN ANY EVENT, THE WAY IAM READING THIS IS THE TRANS IS SLIPPING.
MORE THEN LIKELY CLUTCHES ARE BURNED UP OR THE FRONT PUMP OR CONVERTOR ARE FAILING. THIS MEANS THE TRANS WILL NEED TO COME OUT AND OPEN IT UP TO FIND THE PROBLEM,OR JUST REBUILD IT..IF YOU NEED MORE INFO PLEASE GET BACK TO ME,IF NOT PLEASE RATE MY ANSWER,THANK YOU,,, TOM...