Codes P0175 and P0172, a both banks running rich?

Tiny
ADOLFO A AVILA
  • MEMBER
  • 2001 DODGE DAKOTA
  • 3.9L
  • V6
  • 2WD
  • AUTOMATIC
  • 214,000 MILES
I have both banks running rich at this point I have replaced both banks oxygen sensors, IAC, TPS, fuel pump, engine temperature sensor, MAP sensor, checked fuel pressure 50 PSI and still running rich. I also checked for vacuum leaks and passed the test with the smoke machine.
Saturday, September 13th, 2025 AT 7:18 PM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Do you have an exhaust leak? If so this will cause outside air to enter the system and fool the oxygen sensor which will make it run rich.

P0172 - System Too Rich (Bank 1)

P0175 - System Too Rich (Bank 2)

Using a scanner I would check the coolant sensor, if is it stuck cold the engine will run rich, use a scanner to check the engine temp and get back to me, also is the engine misfiring? This will cause issues as well.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please go over this guide as well:

https://www.2carpros.com/articles/why-an-automotive-engine-will-run-rich

Remove the spark plugs for inspection and upload an image in your response so I can see them. Please go over these guides and get back to us.

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Sunday, September 14th, 2025 AT 12:41 PM

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