I have a 2005 VW passat with 160,000 miles on it. If I start the car it idles great for about 1min but I hear a suction noise coming from the passanger side of the car somewere near the turbo and air filter. After the 1min idle the sound stops then the engine starts to idle very poorly and misfires and the check engine light flashes. If I give the car gass then the check engine light stops fasing and the engine runs a lot better but still not quite right. What I have done so far from reading other threads:
Replaced all four coil packs (Which Ive done a few times before)
Replaced the sparks plugs (with NGK double platnium plugs)
Replaced the purge valve (on top of the air filter)
Replaced coolant temp sensor (on the backside of the engine near the firewall)
Replace the crankcase vent valve (on top of the engine near the firewall)
Replave the crankcase breather hose (on top of the oil cooler under the intake)
Cleaned the throttle body.
Cleaned the MAF sensor.
Took off the intake and clean it. (It had a thin film of oil inside it)
Inspected every PVC hose and componants.
Checked all the check valves.
Took of the Fuel rail and cleaned the fuel injectors and replaced the O-Rings
The crankcase vent valve was leaking and the crankcase breather hose was broken in two pieces. I thought for sure that the busted crankcase breather hose would have fix it but it didnt.
I ran the OBD-II codes.
Here are the codes before I replaced the parts listed above.
After I replaced the parts I now have the codes below:
I changed the new coil pack around, erased the codes, drove it about 5 miles and got the same codes.
I unplugged upstream O2 sensor and the car ran exactly the same. Im wondering if it may we the problem as it has 160,000 miles on it.
I am curious if my problem is a faulty catalitic converter, O2 Sensor, or wiring harness for the coil packs. Any advice on how to check these parts as they are all $$$. If you have another idea of what I should check that would be great too.
Thanks in advance.