March of 2020 my service engine soon light came on. Car running great. Was on a few weeks, then off for 2 months. Has come back on and off multiple times. Codes are P1DO which should be an easy fix of replacing the Intake Rocker Arm Solenoid. Then i have the infamous evap code of P0455. Looks like that could be multiple things. Any suggestions on where to start? I have replaced the gas cap. And i am a little puzzled as why it goes off and on. I would think an issue would cause a steady light. So hesitant to start throwing a ton of money at replacing on of six issues it could be and still potentially not have it fixed. Has any one else had similar issues? Like is said, car runs great, biggest down fall right now is I cant use my remote start with this light on and winters in Iowa are cold!

 

P0455 Possible Causes

What does this mean?

• Missing or loose fuel cap
• Incorrect fuel filler cap used
• Fuel filler cap remains open or fails to close
• Foreign matter caught in fuel filler cap
• EVAP canister or fuel tank leaks
• EVAP system hose leaking
• Fuel tank leaking

 

Took the car in last Wednesday to local Chevy dealership. They performed a “smoke test”. Only leak was out of purge valve. They replaced and knock on wood, 5 days later service engine soon light is still off. Diagnostics, part and labor $ 265. Hopefully this took care of it! P1D0 code was fixed under a special Chevy warranty, free of cost.