← Back to list

2010 Ford Fusion P0451 and P1450 EVAP System Fault: Recurring Check Engine Light After Replacements

Model: 2010 Ford Fusion Fault Code: P0451 Posted: 2017-04-19 07:26

My 2010 Ford Fusion has been running fine until recently, when the check engine light came on. The fault codes displayed are P0451 (Evaporative Emission Control System Pressure Sensor Circuit Range/Performance) and P1450 (EVAP System Leak Detected). I replaced the purge valve, fuel tank canister, and canister solenoid—all new parts—based on dealer diagnostics. After resetting the system and completing a test drive with no issues, the codes cleared and emission tests passed. However, after restarting the car in the morning and driving for about five minutes, both P0451 and P1450 returned. All hoses are intact, showing no cracks or leaks. The fuel filler cap is capless and closes properly. I am aware of a past Ford EVAP software update recall from approximately nine months ago; at that time, the vehicle was deemed safe with no repairs needed. The dealer has now advised that the recall inspection is closed and any further repairs are my responsibility. This raises concerns—since the car functioned perfectly prior to the software update, it seems unlikely that a hardware failure would have been triggered by a software fix. I am seeking advice on possible root causes: could there be an issue with the tank vent valve assembly or vent hose/filter? Is there a known TSB (Technical Service Bulletin) for this specific model year and fault code combination? I’ve already checked voltage to the ECM sensors, but no abnormalities were found. Any insights into diagnosing this recurring EVAP system failure would be greatly appreciated.

Related fault codes

P0451P1450

Comments (5)

Anonymous 2017-04-19 08:03

I understand you're dealing with a persistent EVAP issue—diagnostic testing is essential to pinpoint the root cause. While P0451 and P1450 indicate problems in the evaporative system, these codes can stem from various components including sensor malfunctions or leaks. Without proper diagnostics, it's difficult to determine whether the fault lies in hardware (like a vent valve) or software. It’s important to note that even after replacing parts such as the purge valve and canister, recurring faults may point to an underlying issue like a blocked vent line or faulty tank pressure sensor. TSBs exist for certain Ford Fusion models—however, they must be verified based on actual diagnostic data. Before concluding that repairs are outside warranty coverage, ensure all components have been properly tested and documented.

Anonymous 2017-04-19 08:58

Thanks for the response. I replaced the purge valve first, then the canister and solenoid based on a dealer diagnosis—though I did so to avoid additional labor costs (estimated at 2.6 hours). The total time spent was about 20 minutes. I’ve now decided to return to the dealership for a full diagnostic check. In addition to part replacements, I’ll verify that the ECM is supplying correct voltage to all EVAP sensors—this could help rule out electrical issues or sensor inaccuracies.

Anonymous 2017-04-19 09:05

As someone familiar with DIY EVAP repairs, a few additional checks might be worth considering: - Is the gas gauge functioning normally? - Does the vehicle experience any issues when refueling—such as the pump shutting off unexpectedly? - Do you typically refill the tank to the top (i.e., 'top-off')? If not, it’s possible that a vent valve assembly or vent hose/filter is clogged or malfunctioning. These components are often located beneath the fuel tank and may be difficult to access without proper diagrams.

Anonymous 2017-04-20 11:54

Thanks for the helpful suggestions. I’ll go under the vehicle tomorrow to inspect the vent line and check for a vent valve or filter assembly. I’ve not done this before, so it’s an important step. The gas gauge works perfectly, and there are no issues during refueling—no pump shutdowns. I generally stop when the tank is full and never top off, which aligns with standard fueling practices.

Anonymous 2017-04-21 09:34

The dealer recently suggested that a single-piece line connecting the fuel tank to the canister solenoid—and containing the tank pressure sensor—is defective. This would explain why the codes return after reset. However, I find this repair estimate—$700+ for both part and labor—to be excessive given the history of prior repairs and the vehicle’s otherwise reliable performance. I’m now evaluating whether to pursue this diagnosis or seek a second opinion from an independent technician with access to Ford-specific TSBs.