Dakota Durango Forum banner

1 - 2 of 2 Posts

3 Posts
Discussion Starter · #1 ·
Fully rebuilt engine with ~400 miles so far, have P0172 bank 2 running rich code and P0300 random misfire. Truck runs a little rough and noticeable power loss. If batteries disconnected and reconnected, codes clear and truck runs GOOD. After some driving codes come back and it runs rich again.

Have hooked up snap-on scanner and looked at fuel trims and misfire counters, no cylinders were currently misfiring when I checked it, but fuel trims were all at -99%. Quick fix with scan tool said bank 1 sensor 1 O2 sensor. Replaced it and same issue. I have cleaned the throttle body best I can also.

New NGK 7098 plugs, New coil packs, new injectors, New OE 190 degree thermostat....

If anyone has any information in regards to assist in the diagnostics of this issue, it would help. Thanks.

66 Posts
I had a P300 error code one time that was just a gas cap that no longer sealed. Here is a list of potential P300 causes that including some that you have already addressed. Vacuum leaks is a big one.

What causes the P0300 code?
  • Spark plugs that are damaged or worn
  • Spark plug wires and/or coils that are damaged or worn
  • Distributor cap that is damaged or worn (only if applicable to the vehicle)
  • Rotor button that is damaged or worn (only if applicable to the vehicle)
  • Fuel injectors that are defective
  • EGR valves or tubes that are clogged
  • Ignition timing that is off
  • Vacuum leaks
  • Fuel pressure that is low
  • Head gasket(s) that are leaking
  • Distributor cap that is cracked
  • Camshaft sensor that is faulty
  • Crankshaft sensor that is faulty
  • Mass air flow sensor that is faulty
  • Oxygen sensor that is faulty
  • Throttle position sensor that is faulty
  • Catalytic converter that is faulty
  • PCM is faulty
1 - 2 of 2 Posts