Have 1999 Mazda 826, 4 cyl–works good. Three times in last year eng light goes on. Each time I’ve had it hooked up to diagnostics. Each time code P0442 comes back small evap leak. Each time nothing is found. However, this last time, light did not go off-I’m not sure they cleared code. Car shop recommended I take it to dealer and have computer/engine reflashed if the light bothered me. Well, it does bother me. What if another problem occurs and a signal/message is not sent out. What are other thoughts or opinions?
Evap system is gas tank filler tube check valuve,vent hose to charcoal canister,hose from canister to intake and gas cap.
Make sure to tighten gas cap 3-4 clicks and do not fill past first cutoff. check seal on cap and go from there.
Thank you very much–I appreciate the suggestion.
Considering the age of the car, it might be due for a replacement gas cap.
I will add one more possibility, if you are in the habit of topping off the tank when filling it up, you could have damaged the charcoal filter and may need a new one. If it has not been topped off, then this is far less likely.