P0421 Diagnostic Trouble Code Discussion for October 2013
Warmup Catalyst Efficiency Low (Bank 1)
Note: This is a professional automotive technician's resource.
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.Trouble Ticket Help Requests for DTC P0421
| Help Request | Posted | |
| 2003 Volkswagen Passat GL 2.8L Misfire cyl #3 VIN: WVWTH63B63 P0421: Cat converter efficiency b1. THIS 2.8L V6 HAD A CONSISTENT MISFIRE AT IDLE ON CYL#3. THE MISFIRE COUNTER JUST KEPT COUNTING UP ON THE VAG-COM AS THE ENGINE SAT IN THE SHOP BAY RUNNING AT IDLE. WE SWAPPED THE SPARK PLUGS, FUEL INJECTORS, CHECKED THE COMPRESSION AND THE FUEL PRESSURE, SMOKE... |
October 08, 2013 |
