I got a P442 code a few weeks ago (small EVAP leak) on a '00 D2 and so changed the gas cap. Alas it has come back a few days later, so I'm wondering where to look for the EVAP leak.

I'll tried to listen for a vacuum leak, but can't hear anything (I guess its small too). I had the head gaskets changed in the same period, it there anything around there that they might have dislodged, cracked that might cause it?

 

I would check for leaks around the fuel tank hoses and the carbon canister.

 

I checked around the carbon canister and other EVAP lines and couldn't find a leak. Now a couple of weeks later, I have gained a P1170 code (P1170 Downstream fuel trim malfunction (bank 1) Front sensor aged - rear HO2S adaption too lean/too rich LH bank (NAS and EU-3 only)).

Any ideas if this new code is related?

I suspect I'm going to have to take it somewhere.

 

Your O2 sensors are bad. But I dont think it is related to your EVAP leak. Replace your O2's and see what happens.

 

check to make sure your purge valve is all the way seated on the intake. past that it could be all kinds of things, from the filler neck to the fuel pump, or a number of lines. as far as the 1170 code, you dont have a noticable exhaust leak, do you?


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I think the P442 must be the filler neck because I have difficulty with the gas pump shutoff mechanism.. How easy is the filler neck to remove/replace/fix?

The rest does sound like the O2, on the OBDII the number look a bit on the edge of the ranges and its running a bit rough...

 

Two places to look under the hood everything that hooks to the EVAP canister and back by the filler both have plastic and rubber lines there.
I found mine by filling the tank to the very top, mine was a line in back.

You may have to take it to have the tank pressured up to find it, not something you should do with gas involved.

 

if youre having trouble filling the tank also, it shuts off alot, its your neck. theres a trickle valve towards the top of it, i think you can get just that now, didnt used to be. not hard to replace, neck comes out decently easy.


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