Thread: EVAP delete

so ive heard you can delete your evap system...ive deleted my cat and egr already and would like to get rid of the EVAP system....anyone know how to do this and have a pic to show or explain? thanks! what are the benefits of deleting it? less vaccuum leaks? the connector for vac on my tb is messed up and if i can delete it rather than buy a new one id rather do that lemme know.

There's no real benefit to deleting it, other than cleaning up the engine bay and having one less thing that can go wrong. All you really need to do is cap off the vac fitting on the TB and cap off the line going back to the tank, then remove the lines/valve and set the codes to not report. Personally, I would also unplug the vent valve back by the fuel filler neck, but it wouldn't be necessary. If you really want to delete the system completely, you'll need to drop the tank to remove the charcoal canister.

I don't see the point in deleting it at all. It just recycles the gas fumes from the tank. The only time it is a hinderance is during tuning, which you just unplug it for the time being.

Yeah...keep it...it is easier

After spending far too many hours troubleshooting EVAP problems on other cars, I got rid of mine just to save myself the annoyance.

Originally Posted by Scimmia

There's no real benefit to deleting it, other than cleaning up the engine bay and having one less thing that can go wrong. All you really need to do is cap off the vac fitting on the TB and cap off the line going back to the tank, then remove the lines/valve and set the codes to not report. Personally, I would also unplug the vent valve back by the fuel filler neck, but it wouldn't be necessary. If you really want to delete the system completely, you'll need to drop the tank to remove the charcoal canister.

ok where is the vent valve? and where is the tank im assuming its the big black cicrle on the firewall with the big hose from the t tree going to it?

Originally Posted by gotboost3

ok where is the vent valve? and where is the tank im assuming its the big black cicrle on the firewall with the big hose from the t tree going to it?

By tank, he means gas tank. The big black circle is your brake booster.

How can the EVAP effect tuning? I've thought about getting rid of mine to clean up the engine bay, other times I figure I shouldn't dick with it.

Originally Posted by Iron Indian

How can the EVAP effect tuning? I've thought about getting rid of mine to clean up the engine bay, other times I figure I shouldn't dick with it.

During an EVAP purge the trims will go very negative as it balances out the mixture with the extra fumes its pulling from the tank. That can throw off your tuning results. While VE or MAF tuning you should unplug the EVAP solenoid.

Basically it can screw tuning during cruise and idle senerios, right? Not WOT?

Right. It won't purge during WOT.

when i do this delete im assuming i take out the evap canister purge solenoid also?....are there any negative effects to this delete besides having to delete the codes?

Your fuel tank will now build pressure as the fuel evaporates, and any fuel that does evaporate in your tank is now wasted. The EVAP is designed to prevent fumes from being wasted and to prevent pressure build up.

i see ok so then yeah ill leave it and unplug it during tuning then....thanks for info guys....will the dealer sell me just the vac line that goes from the solenoind to the TB because mine is all fukked up

The tank will not build pressure. The vent valve is a normally open type, and the computer only closes it while it's running it's pressure check, otherwise it stays open to vent the tank. The reason I said to unplug the vent valve is so the computer doesn't even close it then, it's always open as it should be. The entire reason for the existence of the EVAP system is to prevent VOCs in the form of fuel fumes from escaping into the atmosphere. The amount we're talking about being "wasted" is negligible.

Originally Posted by Scimmia

The tank will not build pressure. The vent valve is a normally open type, and the computer only closes it while it's running it's pressure check, otherwise it stays open to vent the tank. The reason I said to unplug the vent valve is so the computer doesn't even close it then, it's always open as it should be. The entire reason for the existence of the EVAP system is to prevent VOCs in the form of fuel fumes from escaping into the atmosphere. The amount we're talking about being "wasted" is negligible.

god damnit lol should i delete it or not....and where is the vent valve?

I'm pretty sure the GP is going to be the same as my Regal, so it would be in the driver side rear quarter panel, right by the fuel filler neck.

As for the question if you should or not, that's totally up to you. As I said, there's no real advantage beyond having one less system to worry about.

Originally Posted by Scimmia

I'm pretty sure the GP is going to be the same as my Regal, so it would be in the driver side rear quarter panel, right by the fuel filler neck.

As for the question if you should or not, that's totally up to you. As I said, there's no real advantage beyond having one less system to worry about.

its an electrical connector i unplug right?...i unplugged it....it was in the driver side rear quarter

Yeah, unplugging the electrical connection should leave it open all of the time so the tank vents like it needs to.

mine is gone...... every little weight helps.