P0442

[steve578]

I know there is some content on the other sites around this topic, but I don’t recall seeing anyone actually fix the issue within their threads. I hope to continue that tradition over here.

The Check Engine Light has been popping up every three weeks or so recently. When I pull the code with Durametric, I see a P0442 Porsche fault code 97 - Tank vent system (minor leak). I usually just clear the code and move on my merry way. I decided to try the easiest thing first and replaced the gas cap three weeks ago and cleared the code. Like clock work, three weeks goes by and the Check Engine light comes on again yesterday.

I may actually try to going through the steps to find the source over the next few weeks. It would be nice to clear this up before starting my next project which is replacing the IMS, RMS, clutch, etc. All of which probably don’t need to be replaced, but I’m a gluten for punishment.

[Dgi 07]

Smoke test it.

Before you jump on me and say smoke machines are expensive and you don't feel like burning your throat with a cheap 7-11 cigar, hear me out.

Paint can smoke machine. Bought one for under $50 a few years ago because I was too cheap too buy the full sized unit and the one in shop I work at is either always in use, or broken.
Uses Mineral oil that you can get at your local CVS, Walgreens, whatever.

Finding your leak.

1. Vacuum check PCV valve when closed.

2. If no leak at PCV valve, use the Durametric and close the charcoal canister vent valve (hopefully you can.)

3. Make sure the filler cap is closed tight. Might have to removed panels to inspect the lines and charo

4. Go to PCV valve and disconnect it from the side that attaches to the tank. Pump smoke into the line.

5. Inspect for leak.


Its either the vent valve on the charcoal canister, the charcoal canister itself (have seen them split along the manufacturing seam) the PCV valve, a line or the cap (which you just replaced.)

Good luck.