hi,

I have 122k ml on es330 and just got p0442 code.
I clear code code and re tighten gas cap
yesterday I added gas and tightened cap as required for 3 clicks, but morning the code came back

I never replaced this cap.
How often or at what millage do you replace this cap?
I'm not sure that the issue is the cap, but by reading all recommend to start from this replacement - costs about $22.

Any one tried to fix the cap or gasket? and how?

I checked hoses by removing plastic engine panel, all are look connected
I suspect issue in hose that connects EVAP line between green plastic evap test and metal tube on top of engine as it might be cracked under, but I don't see it from the top.
this hose got very hard and lost all elasticity over time and heat.
Any one know OEM item number for that hose?
I'm not sure generic hose will work in this place due to heat.

thanks for help.

 

Its a no brainer, replace the cap. Get an original one from Lexus/Toyota. Don't waste time and money trying to change the gasket.

Hopefully that solves your problem. But for $22.00 it's worth a try.

Phil