so I was driving my car the other day and it was driving fine but I went to manually downshift my car because I dont like wearing my brakes out. and I noticed when I put it from overdrive Into drive it didn't idle up it stayed at the same rpm. Then when I hit the gas it felt like it was just slipping.

Does it any every gear, i can put it in 1st going 60mph and itll just stay at like 2k rpms but if i just leave car in od it rides fine no slipping or anything, is it just a solenoid im missing. Or is something wrong in the trans?

Car is a 1995 camaro z28
165k miles
4l60e
Mostly stock car

 

Is the transmission original to the car?

Start with the normal... make certain the the fluid level is properly full.
I would then want to make sure that the transmission is being commanded to the gear, that you intend via the gear-selector.

Note: A stock 4L60E should NOT downshift to 1st gear at 60 Mph when the gear-selector is moved to the 1st gear position.
The logic will prevent the command of first gear in this situation, to protect the transmission and engine from damage.
There is a lot more to go over regarding this... but I would start by getting equipped to be able to view which gear is getting commanded.

 

Codes?