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Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Car
Satisfied Customers: 1176
Experience:  16 years of experience
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My check engine light came on and I took it..gas cap..tightened

Customer Question

My check engine light came on and I took it to my mechanic. The code said it was the gas cap. He tightened it and it went off. A couple days later it came back on. So I bought a new gas cap. Its still on after all this. Any suggestions as to what I might do?
Submitted: 6 years ago.
Category: Car
Expert:  Ron Z. replied 6 years ago.

Welcome to! My name is DriveFast71(Ron) and I will do my best to answer all of your questions completely and accurately.


Did you happen to get the "p-code" that was retrieved pointing to a faulty fuel cap? Was it P0455?


Customer: replied 6 years ago.
All my mechanic said was he checked the code and it was the gas cap. I never got the specific code though.
Expert:  Ron Z. replied 6 years ago.

ok- unfortunately, there are a ton of parts/sensors monitored in the EVAP system. To "correctly" diagnose this, we'll need a p-code. With this p-code I can provide a better insight as to exactly which part/sensor has the fault, and then steps to check/correct it. On some EVAP p-codes, there are even Toyota issued Technical Service Bulletins which will related defect items that may cause the code- some even covered by warranty depending on milage. Without a p-code, we're just "guessing" and that will get costly and fustrating very quickly. You can have these p-codes read for Free at any local "big chain" parts store (AutoZone, PepBoys, etc).


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