Hi everyone, first post here so hopefully this is where I should be. I recently bought a 2002 Jetta 1.8T with 185000km. Car was well cared for, runs great. One day when I was driving the MIL started flashing and the engine was running very rough - only 3 cylinders were firing. Took it to the dealership, and it was throwing fault codes indicating a misfire on cylinder 3 - open circuit on the injector. Dealer replaced the overlay harness to NO2 injector, cam sensor, which seemed to fix the problem. Engine ran great, no MIL.
The next day the MIL came on again, not flashing this time, and the car ran fine. Took it to my mechanic, who found the following fault codes:
17511 - 02 sensor cicuit bank 1, sensor 1, output too low
16684 - random misfire detected
16685 - cyl1 misfire detected
16804 - cat sys bank 1 eff below threshold
17956 - boost pressure contol valve open
17939 - intake camshaft control circuit open
17695 - turbocharger bypass valve open
17645 17647 17648 17646 - fuel injector circuit open on cyl 1,2,3,4
We cleared the codes, but light came on later the same day. I haven't run the codes again, but I'm sure they are the same as listed above . The engine is running perfectly, so I am unsure why these same codes are popping up.
I would really appreciate any input you guys might have on this. My thoughts are that there is a problem with the new overlay harness that was installed. FYI, the coils have been replaced on recall, so no issues there. My mechanic also recommended that I replace my spark plugs, but I doubt that fouled plugs would cause all of these codes.
The next day the MIL came on again, not flashing this time, and the car ran fine. Took it to my mechanic, who found the following fault codes:
17511 - 02 sensor cicuit bank 1, sensor 1, output too low
16684 - random misfire detected
16685 - cyl1 misfire detected
16804 - cat sys bank 1 eff below threshold
17956 - boost pressure contol valve open
17939 - intake camshaft control circuit open
17695 - turbocharger bypass valve open
17645 17647 17648 17646 - fuel injector circuit open on cyl 1,2,3,4
We cleared the codes, but light came on later the same day. I haven't run the codes again, but I'm sure they are the same as listed above . The engine is running perfectly, so I am unsure why these same codes are popping up.
I would really appreciate any input you guys might have on this. My thoughts are that there is a problem with the new overlay harness that was installed. FYI, the coils have been replaced on recall, so no issues there. My mechanic also recommended that I replace my spark plugs, but I doubt that fouled plugs would cause all of these codes.