1998 corolla po446 comes on every 90 miles driven.

Question

change gas cap and canister still po446

Answer 1

P0446 Evaporative emission vent control malfunction

One place and one area that is commonly overlooked, the most common cause for this code, beside the vent control, check this area first. at the aircleaner  to the throttle body there is a air duct if it is torn or rip not only will not filter incoming air it will also set a P0446. If it is rip or has tears in it do not tape it to seal it, replace it.