I seem to be having a few problems with my wife’s 1998 T5 and am wondering of they are all linked together. First my check engine like has been on for a while. I took into the dealer and they said it was a code they’d never seen before, something between the mass meter and the oxygen sensor. So they reset it and the light was back on a week later. Now they want to swap out the mass meter. My recollection (on the 240’s) is they when they go, the car just won’t run. So I didn’t swap it out. Now I’ve noticed that the temperature seems to be in the bottom third of the gauge when driving only to normalize in the center of the gauge at stop lights. I also noticed today that the coolant system seems to be under a lot of pressure (based on squeezing the top rad. Hose.) This is after a huge hill where I know the motor must be hot! I was thinking that maybe I should change the thermostat but then started to worry about all the electrical gizmos. Maybe it’s running rich? Therefore cold? But that wouldn’t stop the thermostat opening? Also the other day, my wife said when she started it up from cold it revved up to about 3000RPM and stuck there for a while. I know that I have a problem with the heater core, love the fog!!!! But If anything that little leak should reduce the pressure on the system. I sure do miss my 122’s.

Any help would be greatly appreciated.