Fuel Tank Ventilation Micro-leak - how many hours of service?

[siddharth]

Hi guys,

I got the CEL and my Durametric read out the error code P0442. Since I've been super busy recently, I did a quick test and then I took the car into a local mechanic shop instead of working on it myself.

I understand there are 3 main sections/steps to look deeper into (also check the attached system diagram):

P0442 Repair Outline:

Section 1. Check "tightness" (i.e. ability to hold vacuum) of shut-off value

Section 2. Check ventilation lines for leaks

Section 3. Check tightness of EVAP canister purge valve

(I did a quick test on Section 3 since I can access this valve from the rear. Testing just the valve seemed to indicate it works alright).

The shop seemed to have done only section-1 (from tech's hand notes).

Section 1 is basically:

1-a ) Remove front right-hand wheel housing liner.

1-b ) Test the shut-off value (i.e. apply battery voltage and create vacuum -> see if it holds)

1-c ) Replaced the shut-off value (since it didn't hold pressure)

Just for 1a-1c, they've have charged me ~3.5 hours in labor @ about $110/hour. That's ~$ 385 in just labor for 1a-1c. This is a 3rd party independent mechanic, California.

I have 2 questions

1) I think it should NOT take a professional mechanic, specializing in Porsches, 3.5 hours to do just the section 1 work. That's just my opinion.

So, how long do you guys think it should take for a shop to perform just the section 1 repairs?

2) Next, how long do you think it should take to perform the section 2 repairs i.e. check the ventilation lines for leaks?

I just got the same error code (P0442) back and since they might have done section1 and I did a quick test on section 3, I might need to revisit the shop to get section 2 done. So some knowledge would be helpful.

To those who don't know, section 2 details are at the bottom of this post:

This story is far from over ... sigh!

Thanks!

Sid

===============================================

Section 2 details:

Use a HC (HydroCarbon) tester and to check the following locations (also check the diagram below)

2-a ) Tank cap

2-b ) Line connections to EVAP canister

2-c ) EVAP canister

2-d ) Line connection to fuel tank sender unit

2-e ) Pressure sensor

2-f ) Opening of fuel filler neck into tank

2-g ) Line connection of EVAP canister purge valve

2-h ) Ventilation lines:

2-h-i ) from EVAP canister to operating purge valve

2-h-ii) from operating purge valve to tank

2-h-iii) from EVAP canister to EVAP canister purge valve

Any reading over 1000ppm is bad and under 50 ppm is good.

Edited January 31, 2011 by siddharth

[wvicary]

The labour rate seems excessive. The first thing to inspect is the fuel cap seals and replace the cap if suspect. I never fault trace codes unless they return after being cleared and a smoke tester is the best tool for checking for leaks in the EVAP system. It's best to just clear the code and play a waiting game to see if it returns.

[siddharth]

The labour rate seems excessive. The first thing to inspect is the fuel cap seals and replace the cap if suspect. I never fault trace codes unless they return after being cleared and a smoke tester is the best tool for checking for leaks in the EVAP system. It's best to just clear the code and play a waiting game to see if it returns.

Thanks for the response! Come to think of it, I forgot to mention a few things that you raised:

- I did replace the fuel cap with a newer cap

- this code does keep coming back ... **** P0442! Played this game for several weeks and MANY times :(

[Ahsai]

+1 on smoke machine since your code is indicating a small leak so it's hard to detect even if they were to vacuum test every single EVAP line. Otherwise, I'm afraid it's a fishing expedition :(

Oh on the bright side, at least it can be reproduced and it's not intermittent so hopefully easier to track down.

Edited February 1, 2011 by Ahsai

[luvmy911]

I know this thread is quite old but was there a resolution? I too have the same issue and have tried all the vacuum tests, repairs and cap replacements. But still every 100-150 miles the CEL pops up with p0442. Any suggestions appreciated! Thanks!

[haimiko]

Having the same issue. Anyone have any additional information on how to resolve this?