I have been getting the 0442 code frequently. The check engine light comes on once the fuel gauge reaches 3/4 and goes out when I fill the gas tank. It will do this everytime. I did install a new GM gas cap but it didn't help. Any ideas?

P0442 is an Evaporative Emissions system Small leak. Check vacuum lines and all evap lines running from the tank to the evap solenoid on the block. There is quite a bit of diagnosis involved in isolating a leak, but more then likely its a purge solenoid leaking.



Buildin' n' Boostin for 08' - Alex Richards

EVAP small leak. Best bet is to take it to dealer. There is a way to fix it, but I never mess around with the EVAP stuff

Thanks Alex, I'll start at the purge solenoid first. Maybe a line has a small hole in it. Thanks.

Paul wrote:Thanks Alex, I'll start at the purge solenoid first. Maybe a line has a small hole in it. Thanks.

Thats typically what the issue is which is why it is difficult to isolate the leak. But the purge solenoid is under the car with all the salt water and road grime so they are most likely to fail.


The VCM will ONLY initiate the OBD test of the Evap system between 3/4 and 1/4 of a tank, thats why the check engine light is on between those points..



Buildin' n' Boostin for 08' - Alex Richards

I'll check this out soon and I'll let you know what I find. Thanks again. Much appreciated.