I have a check engine light on. the code is P0442. Ive changed the gas cap and the light turned off. a couple of months and now it's back on. anybody have any idea what else it might be??

 

I had the same issue about a month ago and it was my gas cap, had the code cleared and had been good ever since. But in your case may be a EVAP leak.

 

what's a EVAP leak?? is that expensive to fix??

 

This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

Symptoms
You likely won't notice any drivability problems.

Causes
A code P0442 most likely means one or more of the following has happened:

A loose or improperly affixed gas cap
A non-conforming gas cap (i.e. not factory/original brand)
A small leak/hole in a fuel vapor hose/tube
Other small leak in EVAP system
Faulty vent o-ring seal
Possible Solutions
With a P0442, the most common repair is to:

Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
Otherwise, replace the gas cap, or
Inspect the EVAP system for cuts/holes in tubes/hoses

 

it can be expensive to fix but just do what SxExCx sujested with the gas cap get the code cleared and go from there. Or it can be the sensor to the filter in the tank.

 

thanks