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I have a 1995 ford t-bird 4.6 v8. my "check engine light" came on. my code reader gave codes 171 and 174 (too lean mixture). I then checked with a fuel pressure gauge and it gave me a reading of 31 psi. what really stumps me is that when i let the engine get hot (meaning turning on the car and letting it run) it runs fine. I changed the fuel pressure regulator and the fuel filter but i still get the same codes and pressure. i had to get a smog check on my car so what i did was let the engine get real hot and it passed! could you please tell me what the problem is and how i could fix it, what parts and tools i need. thank you.

Optional Information:
1995 Ford thunderbird 4.6 v8

Already Tried:
changed fuel pressure regulator, fuel filter and both oxygen sensors

Customer (name blocked for privacy)

Status: Closed Value: $15

Thanks for the question.

First double check for any vacuum leaks, especially around the PCV area.

Then if that is ok, remove the MAF sensor "mass airflow sensor" that is on the air filter box. Get some brake cleaner and spray down the 2 small wires in the airflow opening. The blow it off with compressed air. Reinstall. Unplug the battery for 15 minutes and drive and retest for codes.

Thanks

Fordanswerman

FORD MOTOR COMPANY CAR AND POWERSTROKE SPECIALIST FOR OVER 16 YEARS. ASE MASTER SINCE 1991. CURRENTLY WORK AT A MAJOR FORD DEALERSHIP. GIVE ME YOUR FORD PRODUCT QUESTIONS, IF I HELPED, PLEASE HIT THE ACCEPT BUTTON. EXPERTS QUESTIONS ON FORDS WELCOMED

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