CEL light and code

[Jack Countryman]

The CEL light came on about half way to work this morning, and remained on
the rest of the day. I dug out the reader and got a code of:

PO 442 01

The PO 442 shows in the manual as 'evaporative system leak, small'. No info
on what the 01 part means.

I used the clear button, but the code immediately returns. I've removed,
cleaned and re-seated the gas cap which caused the last such error several
months ago.

Ideas on what else to check for? Or ways to find whatever leak there is
without a trip to the dealer?

Thanks.

 

[mulder]

The CEL light came on about half way to work this morning, and remained on

the rest of the day. I dug out the reader and got a code of:

PO 442 01

The PO 442 shows in the manual as 'evaporative system leak, small'. No info
on what the 01 part means.

I used the clear button, but the code immediately returns. I've removed,
cleaned and re-seated the gas cap which caused the last such error several
months ago.

Ideas on what else to check for? Or ways to find whatever leak there is
without a trip to the dealer?

Thanks.

In addition to the fuel tank itself, the filler neck, fuel pump
gasket, etc. there are also the components of the evaporative system
including the charcoal canister, various valves and solenoids and the
hoses connecting them. There can be a leak at any point that will set
a code. Exactly what components you have and where they are depends on
what model car you have.
Unfortunately, small evap leaks can be difficult to troubleshoot.
Sometimes the only way to find them is with a smoke machine which
means a trip to a shop.

 

[Todd H.]

The CEL light came on about half way to work this morning, and remained on
the rest of the day. I dug out the reader and got a code of:

PO 442 01

The PO 442 shows in the manual as 'evaporative system leak, small'. No info
on what the 01 part means.

I used the clear button, but the code immediately returns. I've removed,
cleaned and re-seated the gas cap which caused the last such error several
months ago.

Ideas on what else to check for? Or ways to find whatever leak there is
without a trip to the dealer?

I might start with a simple gas cap replacement. I'd be willing to
bet it's the most likely cause for an evap sensor to trigger.

On a semi related note, my last vehicle failed emissions here in IL
because of it and all it needed was a new gas cap. THey test the gas
caps independently which, one would reason, is because they are
frequently a problem area.

Best Regards,