I started this string over a year ago (see below). My car continues to suffer the same problem. It now has 62,000 miles on it. I finally decided to take it to the dealership seeing as my local mechanic and 2 VW specialists could not figure out what is wrong - 2 new sets of coils, 2 news sets of spark plugs, and several expensive diagnostic tests that reveal nothing later. The dealership also has no clear idea what is wrong with the car and VW itself has not been any help either (rather useless really). No service bulletins have been posted for my car. I have tried several additives (Techron, Sea Foam) but that did not yield any results. The one thing I have noticed is that the misfiring ceases to occur when the gas tank is a little less than half full but begins to occur again as the gas gauge reaches the refill zone. It misfires like crazy when the tank is full. I am thinking of replacing the wiring harness for the fuel injectors but this is yet another best guess as to what might be wrong with the car. Any assistance in helping me solve this problem is most greatly appreciated as this car is driving me crazy!
I have a 2006 Jetta with a 5 speed manual transmission and 35,000 miles. The engine randomly misfires causing it to stutter or stammer. The check engine light is on and has been for several weeks. Occasionally the check engine light flashes. I took it to a local mechanic who ran a series of diagnostic tests (no vacuum leaks) and they recommended having all the ignition coils replaced for all 4 cylinders. They also replaced the fuel filter. I did so but the problem soon returned to which they referred me to the dealer. I decided to take it to a VW specialist in town and they replaced the spark plugs for all 4 cylinders. They noticed that some of the plugs were black with a buildup and some were clean. The VW specialist also recommended that I take it to the dealership as they too had no clear idea as to what the problem is. I finally took the car to the dealership and they also had no clear idea what is wrong with the car. I have tried several additives (Techron, Sea Foam) in the hopes that cleaning any carbon build up The car did suffer rodent damage in 2007 but was still under warranty so all the wiring that had been chewed on was replaced. I use premium gas. I would like to fix the problem to avoid any catastrophic failure but am trying to avoid throwing money away on any more guess work.
P0202 - Injector Circuit Open Cylinder 2
P0300 (2 separate listings) - Multiple Misfire Random
P0302 (2 separate listings) - Multiple Misfire Cylinder 2
P0304 (2 separate listings) - Multiple Misfire Cylinder 4
P0301 (2 separate listings) - Multiple Misfire Cylinder 1
P0201 - Injector Circuit Open Cylinder 1