i have a 1999 ford ranger 4.0l 4x4 with p0171 and p0174?


Asked by Dec 08, 2013 at 06:20 PM about the 1999 Ford Ranger XLT Extended Cab Stepside SB

Question type: Maintenance & Repair

I have p0171 and p0174 codes, I have replaced the upstream o2 sensors, fuel filler neck, mass air flow sensor, ect temp sensor and I still have the check engine light come on!  I am running out of ideas.  I know the intake is not the problem I have tested that.  what else could it be???

6 Answers

Tom Demyan

Those 2 codes are always related to a vacuum leak. Check all your hoses and intake gaskets.

1 out of 1 people think this is helpful.

how do you check intake gaskets? I have sprayed them with carb cleaner and the truck does not sputter?

1 out of 1 people think this is helpful.

I'd simply REPLACE all vacuum lines with silicone rubber and be done with that forever~

1 out of 1 people think this is helpful.

Clean the MAIN 1/0 battery cable from the cable to the chassis...wirebrush the end of the cable and wirebrush the chassis....put 'em together for a renewed system ground...the ECU does not work properly when it cannot have steady voltage and steady amperage....reset the trouble codes with a handy 20 dollar scanner~

1 out of 1 people think this is helpful.
Tom Demyan

Professionals use a smoke machine. You can also turn the car on and move the hoses around with your hand if nothing came up with the carb cleaner method. If you hear hissing, you found it.

1 out of 1 people think this is helpful.

Check your fuel filler pipe vent line. Mine was rusted away.

1 out of 1 people think this is helpful.

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