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K. Wiggins
K. Wiggins, ASE Certified Technician
Category: Chevy
Satisfied Customers: 2912
Experience:  ASE Certified Technician, Associates Degree in Automotive Technology, 15+ years in the trade
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I have the code you needed to better help me it is P0455

Customer Question

I have the code you needed to better help me it is P0455 evaporative emissions (EVAP) systems large leak.
Submitted: 9 months ago.
Category: Chevy
Expert:  K. Wiggins replied 9 months ago.

Good morning, when PO455 sets it means there is a large leak in the evap system or a problem with the evap purge system.

The most common cause of this is a bad gas cap. If you haven't already I would replace that first.

If the gas cap does not solve the leak the vehicle will need to be smoke tested. This is a procedure where a special machine is used to introduce smoke into the EVAP system to find the leak.

I'll post manufacturer troubleshooting info on this below for your reference.

Customer: replied 9 months ago.
thank you for your help.
Expert:  K. Wiggins replied 9 months ago.

You're welcome, it's my pleasure. Thank you for using Just Answer!