Since owning the car (12/11) it has been a decent daily driver and hasn't really given me too many problems for a used car. Lately however, I have been suffering some issues that are effecting the driveability and use of the car. Before explaining the issue I will inform of the parts I have changed throughout the last year. From January to current I have replaced the following parts with replacements from ECSTUNING.COM:

Fuel pump
Fuel pressure regulator
Coil packs
Passenger downpipe
Pcv system
Fuel filter
Mass airflow sensor

My current issue is a severe missfire, flashing check engine light and cold start issues. If the car sits for more then four hours it takes several turns of the key to fire up. Due to having replaced the major fuel components, this leads me to believe there is a fuel switch or solenoid that may be bad but I'm unaware of it's existance or location, does such exist?

Next, the missfire rough idle issue. The only engine codes I have pertain to mostly o2 sensors. I do not believe that this will cause the missing and rough idle because it runs fine every other start up. Here are the engine codes I have from vag com scan:

P1394
P1122
P0154
P1140
P1120
P0160

If anyone has any input on these two issues I would greatly appreciate the help!

 

Take care of the CEL's first and when you get rid of them permanently, post here.

 

Is there any other reason besides bad sensors as to why all four of my o2 sensors would not be reading..?

 

Have you replaced your coolant temperature sensor? This could at least contribute to your starting issues.

Are your spark plugs reasonably new? These are a very easy/common source of misfires and they aren't on your list.

 

Yea, replaced my spark plugs about 5,000 miles ago and the coolant temp sensor also. Forgot to add that!