msrdude

i got a 03 navigator and i have been getting a p0456 code for a while and now it gave me a p0456 code and a p0442 code too. Anyone know the problem or should i replace the gas cap to see if it fixes the problem?

Bert

Check for any other lines etc, in the system to see if any could leak. Small leaks are hard to find. I had a piece of hair that was accross the seal on one gas cap that was causing the P0442.
OBD-II Trouble Code: P0456 Evaporative Emissions System - Small leak detected
OBD-II Trouble Code: P0442 Evaporative Emission Control System Leak Detected (small leak)

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Bert

RickMN

Read this post to see how the system works and the likely causes

P0456 and P0442

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I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://www.ricksfreeautorepairadvice.com/

msrdude

I did a smoke test through the green valve thing. I let it smoke for a bit and found no smoke coming out. I wiggled all the hoses to see if that might get the smoke to come out, but nothing as well. I hooked up the Verus scan tool to open and close the evap system and other evap components and they work; I get reading/graph changes. Anyone know what else it could be?

msrdude

Update:

Took it to the Ford dealer, and they told me it was the gas cap. I replaced that.
A week later, the code came back, took it to them, they smoke test the car and found nothing. They added dye or something to the system to hopefullt find it, but did not find anything. They then said there is likely a problem where the gas tank is and they need to remove it to find the source of the problem. Problem is they are charging me too much and why do i have to pay if they did not get it right the first time? (dont answer that).
Does anyone know what could be the problem where the gas tank is?

Bert

They shouldn't keep charging you. Have you talked to the service manager about it?

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Bert

CatSkinner

Are you topping off the tank or do you stop at first click when filling it?

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Prius repellant, just add gas.

msrdude

No, i never fill it to the max. I will take it to my friend to check it out for me. He checks for free so its cool.