code PO446B but thats an EVAP code?

2001 TOYOTA CAMRY SOLARA

157,085 MILES

SLAMMEDSOLARA

MEMBER
1 POST

Run fine but my brakes are rock hard, ive been told several times before that my booster diaphragm is tore , that ive known, but would a booster with a tore diaphragm cause it to get bad mileage, it has a check engine light with code PO446B but thats an EVAP code (Vacuum Switching Valve). i drive 35 miles a day on the highway but i use about 2 or 3 gallon a trip, could this be caused by my brake booster or the faulty VSV?

Nov 6, 2013 at 7:43 AM

SQM

✓ASE Certified Mechanic
6,383 POSTS

Hello,

The code: P0446 - Evaporative Emission Control System Vent Control Malfunction.

This is not related to the brake booster.
The poor fuel mileage issue is likely caused by the EVAP system malfunction.

This code can be triggered by few different reasons. It could be the vent valve, it could be the fuel filler neck, it could be the harness to the valve etc.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have included the complete troubleshooting procedure below. Go thru this to find out the issue.

Please let me know of any questions.
Thank you.

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Oct 1, 2021 at 7:45 PM