p0171 codes?

try cleaning out the passageway to the EGR and also have catalytic converter flow tested. something is probably stopped up and causing oxygen sensors to not work properly. if all is OK replace oxygen sensors

This guide can help us fix it

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Please run down this guide and report back.

Hello, about a month ago, i put in new head gaskets and did valve job and resurfaced the heads. I got it all back together and now im getting a flashing ses (service engine soon) light. I scanned it and got code p0171 only. i hear a slight exhaust leak but done know exactly where its comming from. any help?

1999 mercury sable 159000 miles, 3.0 ohv

Flashing check engine light is an indication of a misfiring and the code p0171 will not cause a flashing check engine P0171 check for vacuum leak and or exhaust leak you had mentioned that you have a small exhaust leak 1st step to correct the P0171 should be fixing the exhaust


DTCs P0171 and P0174 indicate air/fuel ratio is correcting rich for an overly lean condition. DTCs P0172 and P0175 indicate air/fuel ratio is correcting lean for an overly rich condition. Possible causes are:
Fuel system malfunction.
EGR system malfunction.
Air intake or vacuum system leak.
Engine oil level too high.
Incorrect cam timing.
Restricted air cleaner.
Faulty PCV system.

Engine light stayed on, mechanic fixed Vacumn flex line, replaced air plentum vacumn line under intake, cleaned fuel injection throttle body system and mass air flow sensor - took car went 6 blocks - died on me - accelerator starving for gas - what do you suggest?
Thanks, Ruthie

[quote:4f3a029111="Ruthie830"]Engine light stayed on, mechanic fixed Vacumn flex line, replaced air plentum vacumn line under intake, cleaned fuel injection throttle body system and mass air flow sensor - took car went 6 blocks - died on me - accelerator starving for gas - what do you suggest?
Thanks, Ruthie[/quote:4f3a029111]

Hey Ruthie
p0171 indicates a lean condition on one "bank" of the engine and usually does not "kill" the engine. I would recommend your tech:

-verify proper fuel pressure

-scan for any other codes

Let me know and we'll go from there!

Chris

Ruthie, howd you make out?