I have 1998 Blazer with a P0442 error code.
I replace the purge & vent valves and still have the check engine light on.
Can I check the charcoal canister by putting a bypass temporarily in, to see if it'still leaking, before I buy a new one?

 

I have a 99 blazer and the charcoal canister is right behind the rear driver's side tire ! did you change the gas cap and see if that helps ? mine had a e-vap code but I cleared it by disconnecting the battery for about 1/2 hour and the check engine light never did come back on !

 

Welcome to the forum! As you're finding out, guessing gets expensive Best to follow the flow chart, then you'll know what the problem is: https://blazerforum.com/forum/diagno...plained-35144/