97 Ford Ranger-Check Engine light comes on intermit. Code P1445 -Purge Flow Sensor circuit Input High. Means?

Well, for one thing you need to find a mechanic who doesn't tell you "Don't worry about it!"

HW33 DTC P1445: CHECK PF SENSOR HIGH VOLTAGE TO PCM

Continuous Memory Diagnostic Trouble Code (DTC) P1445 indicates that Self-Test has detected a PF sensor circuit input above the maximum.

Possible causes:

PF shorted to VPWR.

PF open circuit.

PWR GND open circuit.

Damaged purge flow (PF) sensor.

Damaged PCM.

Disconnect PF sensor.

Check for loose pins or broken wires by pulling moderately on the PF and PWR GND circuits at PF sensor harness connector.

Repair as necessary.

Reconnect PF sensor.

Connect scan tool.

Key on, engine off.

Note: PF sensor input to the PCM range is 0.40 to 4.80 volts.

Access EVAPPF PID.

Key off.

Was EVAPPF PID voltage greater than 4.80 volts?

Yes No

GO to HW34 . Fault is an intermittent DTC P1445. GO to HW39 .

HW34 CHECK VPWR RESISTANCE FOR SHORT TO PF CIRCUIT IN PF SENSOR

Key off.

Disconnect PF sensor.

Allow the vehicle and PF sensor to cool down or warm up to a room temperature 13°C to 27°C (55° F to 80°F) before taking a resistance measurement on the PF sensor. This can take 15 to 20 minutes.

Measure resistance between VPWR and PF pins on the PF sensor.

Is resistance between 40 and 230 ohms?

Yes No

GO to HW35 . REPLACE damaged PF sensor. RESTORE vehicle. GO to HW42 .

HW35 CHECK PF SENSOR VOLTAGE INPUT TO PCM

Key on, engine off.

Measure PF circuit voltage at PF sensor harness connector to battery negative post.

Key off.

Was voltage greater than 10.5 volts?

Yes No

GO to HW36 . GO to HW37 .

HW36 CHECK PF CIRCUIT FOR SHORT TO VPWR IN HARNESS

Install breakout box, leave PCM disconnected.

Key on, engine off.

Measure resistance between PCM test pin 11 and PCM test pins 24 or 103.

Is the voltage greater than 10.5 volts?

Yes No

REPAIR short circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test . REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test .

HW37 CHECK PF CIRCUIT FOR OPEN IN HARNESS

Install breakout box, leave PCM disconnected.

Measure resistance of PF circuit between PCM test pin 11 and PF sensor harness connector.

Is the resistance less than 5.0 ohms?

Yes No

GO to HW38 . REPAIR open circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

HW38 CHECK PWR GND CIRCUIT FOR OPEN IN HARNESS

Measure resistance of PWR GND circuit between PCM test pin 24 or 103 and PF sensor harness connector.

Is the resistance less than 5.0 ohms?

Yes No

REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test . REPAIR open circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

If none of the above makes sense to you, find a different mechanic and let him look.

My 93 ranger did the same thing once I passed 100K or 150K miles. It has been doing it ever since. I don't even have the same engine in the vechiel and the light still comes on.

I'd be pretty peeved at that mechanic though.

Go to Autozone or Advanced Auto and have them read the codes stored on the engine. Then you will at least know more about what you are dealng with. Start there it may be something you can fix with thier guidance. If all else fails.......... add Marvels Mystery Oil to gas and oil as directions indicates.

PF(purge flow) sensor could be bad,disconnected,shorted to power.....or bad PCM(computer).Any way you need good diagnostic mechanic to look in to it.