'96 No power >40mph

'96 Jetta 169,000 mi. Will not accelerate. Cannot get up hills or past 40mph unless I'm cruising on flat strip for a long time, then I can get up to 50. Otherwise, the more gas I give, the more it chugs and the slower it goes.

Brand new plug wires, fuel filter, & ignition coil. New plugs/cap/rotor past 6 months. Newer exhaust (cat. back), timing belt @ 155K mi. My colleagues say it's a plugged cat. but Midas says no (there would be codes and it would be glowing red-hot if it were plugged). Codes for mis-fire on 3 cyl's, possible PCV or MAF, but MAF looked good, air filter OK. Some oil in intake up to PCV but Autozone guy said a new PCV wouldn't help this prob. Could it be the cat. after all?

I had the same problem and it was a matter of adujusting the throttle cable.

You could have a restriction anywhere in the exhaust and it would cause the problem. As far as it being red hot, maybe / maybe not, it just depends on what it's clogged with. Try to accellerate in a low gear and see if the RPM's climb like they should. If there is a clog, then engine won't run at high RPM regardless of speed. Is your air filter ok? Check for vacuum leaks, Check timing, check your fuel injectors. When you press the accellerator, it opens more air flow and the MAF tell the computer to send more gas through the injectors. If you open more air and the injectors are clogged the mixture becomes too lean.

One more possibiliity, if the fuel pump is going out and can't provide sufficient pressure at higher RPM's you would get the same symptoms. Check fuel pressure.

No power, before you do anything else run a compression check. I have had similar problems and done lots of work on engine and then found it was a bad valve or piston. good luck