Check Engine and Fuel Cap Light

[mcobb]

On my 2006 XLT 4.0...

Check engine light was on when i bought it. Code reads P0455.

I changed the cannister purge valve (as the previous owner told me thats what it needed and the code also mentions it so i figured win-win)- reset the light and it stayed off for a few days.

When fuel level got to about 1/4 tank it kicked back on (Dont know if coincidence or not). Tried resetting battery but after a few days when fuel tank gets on the bottom side, it comes back. Code still reads P0455.

Now, the check fuel cap light came on. It was on secure and correctly so i bought a new gas cap. Reset the battery and it stays off for about a week and this morning comes back on for no apparent reason. It is on the way it should be.

Any ideas on what these issues could be? Do they have anything to do with each other seeing as how the check engine code shows gas cap as a possible cause of the code??

Little things like dash lights bother me so i want to get to the bottom of this.

Thanks!

 

[mcobb]

any body?

 

[Explorer75]

On my 2006 XLT 4.0...

Check engine light was on when i bought it. Code reads P0455.

I changed the cannister purge valve (as the previous owner told me thats what it needed and the code also mentions it so i figured win-win)- reset the light and it stayed off for a few days.

When fuel level got to about 1/4 tank it kicked back on (Dont know if coincidence or not). Tried resetting battery but after a few days when fuel tank gets on the bottom side, it comes back. Code still reads P0455.

Now, the check fuel cap light came on. It was on secure and correctly so i bought a new gas cap. Reset the battery and it stays off for about a week and this morning comes back on for no apparent reason. It is on the way it should be.

Any ideas on what these issues could be? Do they have anything to do with each other seeing as how the check engine code shows gas cap as a possible cause of the code??

Little things like dash lights bother me so i want to get to the bottom of this.

Thanks!

http://www.obd-codes.com/p0455

Asuming you installed an original Motorcraft gas cap then you should follow:

Inspect the EVAP system for cuts/holes in tubes/hoses (you may hear a vacuum noise or smell fuel), repair if necessary.

 

[pzman]

I have the same problem. Bought new cap and replaced. Idiot lights came back on. Had system smoked. Gas tank vent valve is what mechanic said. It is a valve to the rear of the fuel tank with electrical and connector and vent hose to it. I am searching on how to remove/replace this valve. Another mechanic really didn't know how.

 

[mcobb]

I took the positive post off battery for about 20 minutes and lights went off. Been off for about 2 weeks now. Just a matter of time before it comes back on I'm sure.