Small Evaporative Leak P0456 and P0442

[HMSEndeavour]

Anyone have any experience with this?

My check engine light came on about 6 weeks ago with code P0456, which is "P0456 Evaporative Emissions System - Very Small leak detected". I cleared the message after checking I had the fuel cap on correctly.

Yesterday, the check engine light turned on again and this time I got code P0442 "P0442 Evaporative Emission Control System Leak Detected (small leak)". I ordered a new fuel cap to be safe. A recent trip (regular old highway) suggests that my fuel efficiency is the same as before so I am not sure if it is a problem worth looking into.

Is this just two variants of the same code or is the EVAP leak getting bigger? How do I check for a puncture in my hoses? Bring it to a garage with a smoke machine?

Thanks!

 

[Toasty]

I pressurize it with a bike pump then use soapy water, common areas are the hoses coming down from the filler and up to the charcoal canister.

 

[evomaki]

Toasty, this is good info. I have the same issue on both of my gen 2.5's. I more or less live with it. Researched to some extent and made some half hearted attempts to fix. But more to your point, I presume one needs to drop the tank to do this? And then up to each individual's creativity to rig up a schrader valve to the filler neck so as to pressurize with bike pump (probably a pvc pipe cap with a hole drilled in it and duck tape)?

 

[Inyo_man]

I solved the issue on my '02 by replacing a very small o-ring located on one of the lines that attach to the top of the fuel pump assembly.
The FSM does not show the o-ring. The o-ring is used in one of the fuel lines that has a push-fit attachment. This o-ring is not made of Viton, so they eventually break down. Unfortunately, I was unable to find a Viton o-ring as a replacement.

http://www.pajero4x4.ru/piii/GR00007400-13B.pdf

Cheers

 

[Toasty]

I didn't drop the tank on mine, i just installed a Schrader valve on an old gas cap.