[guard1]

My daughter's 2008 Passat comfort is having issues. First had P0303 DTC. Replaced the spark plugs and it didn't go away. changed the coil pack for #3 cylinder and it went away. P0304 DTC appeared, replaced the remaining 3 coil packs. The code will not go away. Car is running fine, does not stumble or hesitate anymore, but code keeps coming back. Found a TSB in regards to original problem but can't find any other info for fixing it. Can anyone help?

 

[DIY]

What will happen or is likely to happen if you never the source problem indicated by this code, assuming it is valid and not a false alarm?

This answer will decide on how best to proceed.

 

[2001Jettagls]

Swap the #4 coil and plug to another cylinder and see if the code moves to that cylinder.

If you still get a P0304, it could be caused by a bad fuel injector or an intake air leak near the #4 cylinder.

You could try swapping fuel injectors around to see if the code moves.