CEL on at 1/4 in gas tank
Pro Mechanic
Joined: Oct 2015
Posts: 683
Likes: 151
From: Pittsburgh, PA
If I had to guess, its probably an EVAP code. P044X or P045X series. 1/4 tank is probably on the edge of EVAP testing criteria, so I'd bet its something wrong with the fuel tank pressure sensor. P0450-P0454 if I'd make a wager. EVAP codes suck to diagnose, but there are very few components to replace it something has failed. Gotta know the code to start though.
Senior Member
Joined: Jul 2015
Posts: 10,934
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From: Minneapolis
Related codes happen all the time on all sorts of vehicles. In fact, more often on non-Fords when people don't reattach the fuel inlet cap properly (which has a really simple solution). Vapor canister, fuel pump, or sometimes just the fuel inlet can be the problem.
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Junior Member
Joined: May 2018
Posts: 13
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C
i dont think thats it. I’ve tried cleaning it, etc. The onlly thing that’s consistent is that the CEL goes on at 1/4 tank and goes off when its filled to more than 1/4
Pro Mechanic
Joined: Oct 2015
Posts: 683
Likes: 151
From: Pittsburgh, PA
I occasionally get an EVAP code if my fuel filler doesn't seal right, but that's usually right after I fill up my tank. Jamming the fuel nozzle thingy in there a few times is enough to clear it up for me. I agree I don't think that's your problem. Your local Autozone, Advance, O'Reilly etc. will be able to scan for codes for free.