Code P0455 and poor MPG

BUGGYLOVER98

MEMBER
2005 VOLKSWAGEN BEETLE
1.8L
4 CYL
2WD
AUTOMATIC
95,000 MILES

Does anybody know why my bug is burning through gas so quick?
It’s a 2005 1.8l turbo and I’m using premium gas.

It’s throwing a p0455 code (EVAP large leak).

it’s not the gas cap, the mechanic smoked the lines out and can’t find a leak, he check the purge valve I think is what he called it. Can’t figure it out!
Also I can watch the gauge drop an entire notch and then go up a little bit and drop again. It’s moving around weird.
I’m going nuts!
Getting 10/15 MPG.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

If you have a large leak then this means the emissions system that is a closed system has something either leaking externally or the purge is leaking into the engine.

How did he check the purge? It would be the most likely cause if there is no external leak.

As for the fuel mileage, it is unlikely that this code is causing the poor fuel economy but it is possible. So we should get that repaired first and go from there.

I attached the testing that we need to do in order to figure this out.

Once we have that code figured out then we can check fuel mileage again.

Lastly if you are taking this to a mechanic and they cannot figure out how to fix a large leak code, I would recommend another mechanic. These are pretty simple to figure out as long as you understand the system and know what you are looking for. Let me know if you have questions. Thanks

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