2003 pontiac slips on 2-3 shift and does not down shift all the

Common problem with that motor is the intake gaskets fail. It could be that but in reality it sounds like head gaskets are gone

i had the same problem with two blazzers. i changed every sensor didnt do anything, found out it was the torque converter. was slipping

I have a 92 Crown Vic first and second works fine reverse works fine when it shifts in the third gear it goes to slipping and overdraft can you help me fix this problem thank you

Had the same problem. In my case, the wiring harness was scraping against the vibrating motor and wore through the insulation. This caused the computer to think the throttle position sensor was bad and the RPMs were erratic. The engine light came on and indicated TPS. A short time later, more of the wires became damaged and the engine started missing cylinders. My problem was at the top rear of the engine where the harness runs over a metal stud (right behind the valve cover). Check your wiring harness. Not an easy find until you actually look for it specifically.

Check for stuck throttle plate. Check pcv hose that goes to the intake manifold. They get soft and leak, check while running.

its the solonoids on the solonoid block, 3 of them are sticking, there is alot of videos on what to do,on you tube, very common problem, mine runs and shifts great now

bad transmission, it will need rebuilding or replacement. sorry....hopefully this helps

on the older style blazers the fan clutches did fail and would often be misdiagnosed as shifting problems as the clutch engaged and disengaged.... also a hard 1-2 shift can be due to your vehicle storing a transmission fault code in the ecm... some transmission fault codes will put the transmission into a fail safe or limp mode in which it engages high line pressure .... this can cause your hard 1-2 shift and will feel normal most of the time other than that. high mileage on the transmission fluid may also require it to be flushed and have the filter kit replaced

What is your speed at 3k rpm? What rpm would you estimate was previously 'normal' for highway cruising? If your Lexus is auto trans, it could be two things, it's either not shifting into the highest gear, or it's possibly slipping in gear (although I would think that would cause the rpms to fluctuate, not stay at a steady 3k). If it's a stick shift, again, it could be clutch slippage, but my choice from your description would be not shifting into the highest gear. Bring it up to highway speed slowly, counting how many shifts it makes, I.m guessing it's a 5 speed auto, but I'm not sure about that.

Only way rpms will flair is if trans has low pressure at any time (and allowing internal clutches to slip) or, if the lock up converter is not remaining engaged). This is not an engine problem. Someone needs to drive this with a scanner attached and monitor systems.Other than an internal problem, could be a shift control module, speed sensor or even a problem with something as seemingly unrelated as a brake light switch.
To protect your rights under any guarantee, keep good records on what is done to correct your problem. In working on your car, your problem becomes the shops problem 'till it's corrected!!!
good luck