How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GMTechBernard Your Own Question
GMTechBernard, Shop Foreman - GM World Class Tech
Category: Chevy
Satisfied Customers: 2158
Experience:  GM
Type Your Chevy Question Here...
GMTechBernard is online now
A new question is answered every 9 seconds

2003 chevy tahoe. diagnostic codes po 171 mod 10 and po 174 ...

This answer was rated:

2003 chevy tahoe. diagnostic codes po 171 mod 10 and po 174 mod 10 (system to lean, bank 1 & bank 2) have been retrieved. what do i do or check for now?

Spray some carb cleaner around the base of the manifold and see if the idle changes at all. If you have a scanner, you can monitor the fuel trims while you do this. Very good chance that your intake gaskets are leaking, causing a vacuum leak, hence the lean codes.

If that doesn't pan out, measure your fuel pressure, make sure its good, should be somewhere between 45-55 PSI, might be a good time to replace the fuel filter if it hasn't been done in a while.

Good luck and hope this helps.


GMTechBernard and other Chevy Specialists are ready to help you
Customer: replied 9 years ago.
thanks. i will follow your ecomendations