bsewall

I've had an intermittent CEL for the past month or so and a noticeable loss of power and light loss of gas mileage - almost as if the parking brake was stuck up a notch or two.

Last Monday the engine shut off while driving - no sputtering, just off completely followed by a loss of power steering about 5 seconds later. I was only about 1 mile from my house, so the motor was still cool.

When I tried to start the motor from the side of the road it started, but immediately died, so I got the car towed home.

I picked up a Actron PocketScan to pull the codes (I know, a VAG would be better). The only code it threw was P0422 - Main catalyst effinciency below threshold (bank 1). I cleared the code and tried to start the car, which started, but immediately died.

The PocketScan also reports:
4 Incomplete Inspection / Maintenance Monitors (I THINK that means the system reported faults here):
-Catalyst
-Evap
-02 sensor
-02 htr
3 Ready Inspection / Maintenance Monitors (I THINK that means systems are operating normally):
-Misfire
-Fuel
-Comp

The car has 250,000 miles. The motor has about 80k miles (replaced a year ago w/ a used engine). The belts and tensioner were changed prior to putting in the new motor. The O2 sensors and Cat are all original - so about 250k miles, as are the injectors and FPR.

One thing to note is there has been a coolant leak for the past 4 months and I've been putting in tap water from gas stations (ick!). I don't know if the deposits could be hurting something in the motor.

Will bad emissions components keep the car from running all together? Any ideas?

12vB5

I'm not sure about your 1.8T, but on my 2.8 a frayed wire from the power output stage to the coils can cause misfire, stalling, and failure to start up.

bsewall

I would think that is indeed a possibility. The wires are old and brittle, especially being by the turbo heat shield.

Reggie

fuel or spark. - You probably need to get a Bentley manual to trouble shoot your root cause and maybe get a VAG-COM - since you plan to do your own work and your car is so old.