Why code P0446 keeps appearing on my 2004 Mazda Mazda3 2.3L?

Question

I have a 2004 Mazda 3 and a faulty code shows me P0446 I replaced the gas cap with a new one and clear codes but the code is showing up again. What else can I check and how?

Answer 1

P0446 COV (change over valve) EVAP system leak detection pump - stuck closed

When it comes to small leaks the first approach would be with the fuel cap. unsecured fuel cap can cause P0446, fuel cap seal does wear out, and cause EVAP codes condition, so do the EVAP hose and filler neck hose, the best approach is the use of a smoke machine to find such a leak

 

Small leaks are hard to find at this Mazda at the filler neck hose a leak was found