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Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: Ford
Satisfied Customers: 3487
Experience:  Owner at Carolina Auto Service & Sales , 20 years experience in Foreign & Domestic Vehicles
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Getting code 450. and onboard diagnostic say check fuel

Customer Question

Getting code 450. and onboard diagnostic say check fuel filler cap. My truck does not have a gas cap.
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: Still getting 18 to 20. Starts just fine, doesn't miss, etc.
JA: What is the model/year of your Ford?
Customer: 2009 XL reg cab
JA: Are you fixing your Cab yourself? What have you tried so far?
Customer: Yes and nothing yet.
JA: Anything else you want the mechanic to know before I connect you?
Customer: 4.6L
Submitted: 10 months ago.
Category: Ford
Expert:  Chad Farhat replied 10 months ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Customer: replied 10 months ago.
Hello Chad
Expert:  Chad Farhat replied 10 months ago.

hey how are you

what do you mean no gas cap, like it is missing ?

and double check that fault code # 450, it is not a valid code

what the truck doing other that the display say check fuel cap, runs good

what is mileage?

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Customer: replied 10 months ago.
milage is 50,500 It says check fuel filler inlet
Expert:  Chad Farhat replied 10 months ago.

ok so it says that on diagnostic scanner ( check fuel filler inlet )

and says check fuel filler cap on dash ?

and the code is p0450?

Customer: replied 10 months ago.
Code on scanner is po450 . Dash says check fuel filler inlet.
Customer: replied 10 months ago.
The truck doesn't have a gas cap only a gasket around the fuel inlet. The outside door and gasket are the seal. Theh gasket is intact and has no defects. The edge of the gasket is thin like a windshield wiper blade.
Expert:  Chad Farhat replied 10 months ago.

The Code P0452 indicates that the Evaporative Pressure Sensor is indicating pressure change values that are below specification,

1-When the EVAP Monitor test is running , so check . ... The Fuel Tank Pressure sensor mounted on the tank

2-take a look at all vacuum lines in the engine bay and at the fuel tank Evap canister

3- check all fuse that the evap solenoids are function and none of there fuses have blown ?

4-are you having problem filling up gas & spitting gas out ?

Expert:  Chad Farhat replied 10 months ago.

if you can find any visible leaks and all vacuum lines are good,

sometimes the fuel pump module o-ring leaks, you want be able to see it with out a smoke test

and that is done using a smoke machine

Let me know if you need anything else on it ,if you are good , Please Kindly rate me.

Hope I was helpful to you

A Positive Rating is Much Appreciated

This Post Will Stay Open for You To Come back and Ask me Any Follow Up Question You May have on this issue , even after you rate me

Thank You

Chad Farhat
ASE Certified Tedchnician