86 951 Driver

Is there a proper how to delete the charcoal canister on the late model 944? I am chasing down a fuel smell and some people have recommended deleting the charcoal canister and running a vented gas cap instead. How should this be done? How should the lines run?

A.M.H

I too have wondered this, for a long time now. I asked around a while ago, and did a whole crap ton of Google searching to really get no clear answer. There is one thread over on 944 online that you have to use the search function to find, from a member/former member that did that delete. Its almost just enough info to do it, but a couple details to the process that arent known. I have even PM'd him, but got no response

MAGK944

Easiest way to do it and you don't need a vented gas cap.

Locate the gas vent pipe on the firewall, clamp a rubber fuel line to it and route it to your air filter box. Now remove all that junk that the gas vent pipe used to feed, vacuum switches, charcoal canister, etc, and you're done.

You can make a clean install by drilling a hole and silicone sealing a plastic nipple to the dirty side of the air filter box to firmly attach the rubber fuel line, or you can just drill a hole and fit a grommet that the fuel line fits into snugly.

A.M.H

You would want to put that tube venting into your air box above the air filter correct? So as it doesnt get the filter possibly damp from fuel vapors? And I like the press fit grommet idea better than silicone.

thirdgenbird

I put a small filter on the vent line under the car and then removed all the stuff under the hood.

86 951 Driver

What line did you do this with? I have the back all torn apart replacing lines and the fuel level sender gasket to hopefully stop the smells back there. Is it the line that comes out of the plastic expansion tank in the rear B pillar?

Shawn Stanford

Pics or it didn't happen (and I won't be able to figure it out).

Aeropooch

actually depending on what state you live in- that canister is a smog required item...I know here in California they check for it.

thirdgenbird

Expansion tank in the rear pillar? I don't recall this. (87 924s)

I followed the line under the hood to the back of the car (near the fuel tank) and put the filter there. I have it tied up near the top of the tank.

I can try ad get pics sometime but it won't show much other than missing stuff

Yes, I figured it was assumed that modifications like this were done at your own risk. Iowa has absolutely no inspection.

s14kev

I wonder if they would even remotely know where to look given it's hidden in the fender and can't be seen without taking things off.

MAGK944

If you are worried about the filter getting damp, which it won't, feed the line to the "clean" side of the airbox, between the filter and the afm.

You are only seeing vapours through the line and only really when you are driving or filling up gas. Basically only when the gas in the tank has reason to move around.

Many have done it but I don't like the idea of cutting the line underneath and fitting a filter.

1. There is a chance of gas escaping if the tank is full and you corner hard.

2. You will smell gas every time you fill up.

IMO its better to have a closed system through the air box, and also better for the environment if that is a concern to you.

A.M.H

Sweet. Well, sounds like I might be doing this when I replace all my vacuum lines with silicone lines, since I'll be in there.

thirdgenbird

Fuel could theoretically escape but isn't likely. The line is very small, comes off the top of the tank, and there is no air inlet. It would be like trying to shake gas out of a can with a straw at the top and no air vent

My car does not smell like gas when I fill up.

Yes, a closed system would be better, and something I've thought about doing. Vented gas tanks are the standard on non emissions controlled vehicles. My street legal Yamaha motorcycle has a vent right on the top of the tank.