My transmision does not shift up

Foot on the brake before you shift
Lift up lightly on the shifter and wiggle
If nothing pull the center console and check the shifter to see what is in the way

Yes it sounds like your transmission is starting to give.. or your low on fluid

2001 Mitsubishi Eclipse GT Throttle body IAC valve MAF sensor cleaning

Pull that filter off again and you will see transmission shift solenoids.
Sounds like one or more is bad.
Google and youtube this topic first so you can get a better idea.

It could be a faulty or damaged clutch master or slave cylinder or broken release bearing or fork

You add and check the Transmision level at the dipstick location, remove the dipstick and use a funnel to add trasmission fluid, the vehicle should be running and at operating temperture as you check the fluid level for a proper reading.

did you change fluid and filter this is just as important as an engine oil change. also a automatic transmission has things called bands that change the gears and hold overdrive in they also need adjusting every 30,000 miles. if not they will cause your transm,ission to slip. and burn up atf fluid.

give e mail and will send

COULD BE SHIFT SOLENOIDS

have u checked the tranny fluid