Emission OBDII DTC Error code P0451

[cosmo]

Just received engine warning light. Code Reader indicates 2 codes present. Reader indicated P0451 - Evaporative Emission Control System Pressure Sensor Performance and second code to be 'Pending.' I understand that 0451 is measuring Fuel Tank Pressure. Where is the switch and what is the part number?

[drolds1]

Don't make the common mistake of assuming there's something wrong with a sensor when you get a code. The code is telling you that there may problem with the evaporative emissions system, fuel tank pressure sensor , hoses to the fuel tank, a problem in the circuitry itself or the PCM. It needs to be diagnosed properly. Just throwing parts at it may or may not fix the problem. You could end up wasting money on unneeded hardware and frustrating yourself.

 

This isn't to say it isn't the the sensor itself. Just be aware that it may not be.

 

You might want to consider purchasing a service manual.

Edited August 6, 2010 by drolds1

[akirby]

Isn't that the same code you get when you leave off the gas cap? Could also be the evap cannister. Or anything else as Artie stated. At the very least you need a troubleshooting guide. I'd get it to a mechanic to be safe.

[cosmo]

Isn't that the same code you get when you leave off the gas cap? Could also be the evap cannister. Or anything else as Artie stated. At the very least you need a troubleshooting guide. I'd get it to a mechanic to be safe.

 

Gas Cap is good. Think if gas cap is left off, the GAS CAP dash light warning light would light which monitors total loss of gas tank pressure. P0451 monitors Tank Pressure but only after a gas tank has been pressurized. Problem could be a faulty switch or bad canister....goes back to my original question...where is the pressure switch so I can check the hoses? On my 2006, both the canister and switch are not under the hood in a obvious location. They must be disguised under a cosmetic, dirt or ground deflector cover by the wheel wells or radiator; or they are located under the car by the gas tank.

[salgal]

My experience with VAPOR LEAK, Reader code P0456 could be described as a nightmare. It took 3 days to get it worked out, which included getting parts shipped, etc. THE MECHANICS NOTES ARE AS FOLLOWING: "VERIFIED CONCERN MIL LIGHT IS ON PULLED CODE P0456 EVAP LEAK INSPECTED HOSES AND FILLER NECK PERFORMED SMOKE TEST SYSTEM NO APPARENT LEAKS REMOVED PURGE VALVE TEST NO LEAKS REINSTALLED LOWER FUEL TANK AND CARBIN CANISTER NO VISABLE LEAKS BLOCKED OFF FILLER NECK AND VENT STILL LEAKS REMOVED VAPOR MANAGEMENT VALVE SHOULD BE CLOSED INSTALLED VENT VALVE RETESTED FOUND OTHER LEAK RETESTED NOW LEAKING FROM FILLER NECK REPLACED AND RETESTED OK"

 

Cost to me was $585.90. In fairness to the Dealer, they paid for the filler neck and installation, which would have cost me $90 for the neck and two hours labor, approx. $300. They were upset also, and were having a long talk with FORD.

 

The following week I made a 2000 mile trip and ran perfect. Dam it is hard to stay mad at this car.