mike sharples

Has anyone had problems with fuel injectors? My allroad 2.7 has an intermittent roughness!, its best way I can describe it, you feel a miss/rough running through the seat, but the engine is smooth, exhaust flow from tail pipes is smooth. I recently changed the sparkplugs, but no change, scans show intermit P0421,primary cat bank1 inadequate effect, I don't think this is relevant. The other day it almost stalled out when I reversed off the drive, then picked up, was ok again. Why injectors?, I get a strong smell of gas on start up, also, occasionally it doesn't start first time, second attempt ok, again very sporadic. The last vehicle I had(dodge minivan 3.8)had a similar problem, I cleaned the injectors on an asnu machine, got loads more power but after 6 months went poor starting and strong smell of gas, new injectors fixed it. I need to do some more testing but just thought I would throw the question out there

DOALLAR

Mike, I wouldnt rule out the spark plugs - check the gaps (.028-.030). Have you tested/checked your coils on both banks? Then while your in there check injector O-rings.
Yes, the PO code indicates the cat is malfunctioning... this could be cause by a bad 02 sensor..hence the hesitation/miss feeling. Also, a bad 02 equals rich/lean fuel...hence the smell of it during start up and driving. Although this may not be an issue -You can even check/test the fuel sending unit.

Good luck.