Codes P0175 and P0172,a both banks running rich?

2001 DODGE DAKOTA
214,000 MILES • 3.9L • V6 • 2WD • AUTOMATIC
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ADOLFO A AVILA
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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.
Sep 13, 2025 at 7:18 PM
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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.




Sep 14, 2025 at 12:41 PM