Code P0172?

Tiny
MONTASSER
  • MEMBER
  • 2008 TOYOTA TACOMA
  • 2.7L
  • 4 CYL
  • 2WD
  • MANUAL
  • 250,000 MILES
New battery, new alternator, new ground, new 2- O2 sensor, new MAF sensor, new fuel regulator, new TPS sensor, good fuel pressure, no vacuum leak, replace engine control ECM, new spark plug, new coil, new injectors, and the truck running rich with code P0172. Thanks Mo
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Thursday, September 25th, 2025 AT 5:25 PM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,610 POSTS
That is a nice truck thanks for the image. I would remove the new spark plugs and see how they look, please upload an image so I can see.

P0172: System Too Rich (Bank 1)

I have seen a stuck open purge valve or a bad fuel pressure regulator cause this, I would remove the valve to see if you can blow through it and if so the valve is bad, also, remove the vacuum line from the fuel pressure regulator and if there is fuel it is bad as well. Please go over the guide which can explain more.

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

Please upload pictures or videos in your response of any problems so we can see, clear the codes when the repair are completed.
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Friday, September 26th, 2025 AT 10:03 AM
Tiny
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Thanks Ken I will do that and get back to you, Thank you very much
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Friday, September 26th, 2025 AT 11:30 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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Sounds good have a nice weekend!
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Friday, September 26th, 2025 AT 6:25 PM

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