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2005 Volkswagen Passat GL 1.8L Poor Idle Quality, Misfire, MIL Lamp on
Posted to European Driveability on 3/10/2010 11 Replies

I have this Passat come in idling real bad and check engine light blinking. Pulled codes and initially found misfire codes on all cyl's and lean code bank 1. Customer previously had been at VW dealer and they diagnosed as 4 bad coils. They installed new coils and symptoms were gone temporarily. Cust unhappy with dealer so she brought it here. I pulled plugs out of all cyl's and found they were leaned out - super white. Checked gap and they were very much worn. Installed new plugs. Installed air filter (nastiest I've ever seen), and changed oil using 5/30 synthetic. Car ran good for about 5 minutes and then started running poorly the way it did. Cust had to have her car that day, but brought it back today (did these repairs 2 days ago). Pulled codes again just to check, and found same misfire codes, no lean code, but found a new one, P1297 connection turbocharger, throttle valve pressure hose. At this point I am scratching my head. Found TSB about re-flashing ECM if misfire codes and this P1297 are stored, but I have no way to be sure that is the problem. Ohmed out injectors and all ohm out at 13 ohms. Pulled new plugs i installed and they look okay, not white like the old ones, but I don't smell fuel on them either. Pulled oil cap off and have suction when engine running - good thing? I have been reading other tech help requests but am unsure about some things. One tech help had almost exact same symptoms and related repairs, but his fix was a new throttle body. This car is a drive by wire. Checked throttle body, does not look too dirty. I do not hear any vaccuum leaks, but I am going to smoke test intake after I finish this request. I am also going to try a fuel filter and intake cleaning to see what happens next. Any ideas would be greatly appreciated.

Related Repair History
NEW COILS (from dealer), NEW PLUGS (OE), AIR FILTER, OIL (5/30 SYN), OIL FILTER

computer Codes & Descriptions
P1297- CONNECTION TURBOCHARGER, THROTTLE VALVE PRESSURE HOSE
P0301- MISFIRE CYL 1
P0302- MISFIRE CYL 2
P0303- MISFIRE CYL 3
P0304- MISFIRE CYL 4
P0171- BANK 1 SYSTEM LEAN

other Test Results
Ohmed injectors - 13.9 ohms on all four
FIX posted 3/12/2010

Jay from Texas

11 Replies Received (View Replies)

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car Vehicle Data

2005 Volkswagen Passat GL

VIN WVWAD63B55
Engine1.8 L / 4 cyl / GAS
Trans5-speed Automatic (Electronic)
DeliveryFI
EmissionsOBD-II Compliant
SymptomsPoor Idle Quality, Misfire, MIL Lamp On
OccursAlways
Misc.1.8 Turbo

Trouble Codes

P0171Fuel System Too Lean (Bank 1)
P0301Cylinder 1 Misfire Detected
P0302Cylinder 2 Misfire Detected
P0303Cylinder 3 Misfire Detected
P0304Cylinder 4 Misfire Detected
P1297Electrical Load Detector Circuit Low Input