Seeking Advice.... How to build a Massachusetts legal EVAP system.

[JeffS]

I had hoped to see a few 818s at the open house with totally stock, Massachusetts legal EVAP systems so I could ask the builders how they did it. Well... the track cars that were there obviously don't count, the Rhode Island cars are emissions exempt, and a few other cars didn't have inspection stickers. Ughh!

So I'm asking for advice... I've still got everything from my 2006 WRX donor.. filler pipe, plumbing, valves, Charcoal canister etc, and the early FFR gas tank (the one from the hot rod).

This presents several problems...

I can't use two fuel level sensors in series to make the gas gauge work. The evap system will only test itself when the fuel level is between 15% and 85% so if my gas gauge doesn't register correctly there could be issues with the system never testing for leaks and throwing codes.

I don't have enough holes (and big enough holes) in the tank to drop in all the OEM sensors and valves. I read on the forum that some people have epoxied the fuel temperature sensor to the outside of the tank. Can I connect the tank pressure sensor, tank sensor control valve, and the evap line all to the single vent connection that FFR provides on the top of the tank? How do I incorporate the OEM check valve in the vent line that keeps liquid from getting to the charcoal canister?

Also... Do I really need the shutoff valve in the filler neck to capture fumes during refilling? That seems over-the-top too complicated.

At this point I'm thinking of cutting new holes in the top of the FFR tank so that I can install the original OEM stuff back in as it was in the donor, although I've already made and installed the fuel pump mods shown in the early versions of the assembly manual. And I'd be worried about getting everything to seal properly if I went that route.

I'd really like the system to work well enough to not throw any codes with the stock ECU, and be able to breeze through the emission inspection knowing it works as close to stock as I can reasonably make it. Any advice would be appreciated.

Thanks... Jeff

[Buzz Skyline]

Do you know how thorough the inspectors are? If you have a charcoal canister and aren't throwing any check engine lights, I doubt they're going to (or even reasonably could) follow the plumbing to see if all the other bits are included. In that case, just program out the lights in the ECU. It's pretty easy to do with either a Cobb access port or an open source Tactrix cable system. You're going to need one of those anyway unless you plan on going to a tuner (who could turn of the codes for you to).

[904svo]

ODB2.jpg
This is what I did on my kit car to pass ODB2 Evaporative testing

[JeffS]

ODB2.jpg
This is what I did on my kit car to pass ODB2 Evaporative testing

A few questions though....

I'm trying to use the FFR hot rod tank supplied with my 818s kit. Where did you find a 100 ohm fuel level sensor? I hope I can adapt it to work with my tank.

From your diagram, I'm guessing that you epoxied the fuel temperature sensor to the outside of the tank? Can you verify that.

I'll look for the earlier model gas-trap. That's a big help. I really didn't want to carve a big hole in my tank and retro-fit the check valve from the donor tank.

Jeff

[Jaime]

90% of the stuff in the Subaru system is there so that ECU can periodically test if the gas cap has a leak. Does Massachusetts actually check for that feature? I would assume a thorough inspector would care about the presence of a carbon canister and that it is properly hooked up to absorb fuel vapor and then periodically run that captured vapor through the intake manifold. But checking for the pressure test system seems like something they wouldn't do.

Also, the pressure test system doesn't actually make your car run cleaner, it just lights the check engine light when there is a problem you need to address.