my canister is needing replaced. no emissions here and im not gonna pay for another one. i see 1 connection under the valve cover plastic is there 2? much like my momo steering wheel install i installed resistors to keep the airbag light off. can i do the same with the evap once its removed? i understand i need to route a line somewhere once its removed

 

I want to follow this I just broke that fine plastic line with my EVAP system. The little green cap devise. I got fuel hose and am going to replace the plastic. How do you get the ends off?

 

I replaced the plastic line with carb line and it worked out perfect. I removed the ends and plugged it into the evap valve. Removed the Green cap. We have no emisions here.

 

what did you do with the codes? or the connections to the solonoid

 

bump... looking to see if i can just put resistors in the connections to keep the check engine light off..

 

you can try the resistor in the connection...didnt work for me. I was getting a tune anyway (heads and cam swap) so I just had him turn that off at the same time. I got rid of all the lines too. Some said I would have a fuel smell under the hood but after 6 months of daily driving, no adverse smell, no ill effects on reliability/driveability. Hope that helps

 

angled line off intake, into evap solenoid, into 'spaghetti' line, into evap line that runs along fuel line to the fuel tanks, then the carbon can, the carbon can has a 1" rubber hose to a another evap vent/solenoid, also a pressure sensor on the pass. tank

There is info in the roadrace section. Either way, you have two solenoids/valves that will need to shutoff(red plugs, 2 wires each)

 

The PCM runs test on the EVAP system so that, if the system isn't working properly (pressure and vacuum in the tank and solenoids operating at the correct time), it will trip the emissions code.

Have it tuned out of the PCM. Just eliminating the solenoids will not work.

BC

SERVICE MANUAL

Evaporative Emission (EVAP) Control System Operation Description
EVAP System
The evaporative system includes the following components:

The fuel tanks
Evaporative emission canister vent solenoid
Fuel tank pressure sensor
Fuel pipes and hoses
Vapor lines
Fuel cap
Evaporative emission canister
Purge lines
Purge solenoid valve
EVAP Canister




(1) Purge Line
(2) Vapor From Fuel Tank
(3) Air

The evaporative emission (EVAP) control system used on all vehicles is the charcoal canister storage method. This method transfers fuel vapor from the fuel tank to an activated carbon (charcoal) storage device (canister) to hold the vapors when the vehicle is not operating. When the engine is operating, the fuel vapor is purged from the carbon element by intake air flow and consumed in the normal combustion process.

EVAP Purge Solenoid Valve




The EVAP purge solenoid valve allows manifold vacuum to purge the canister. The powertrain control module (PCM) supplies a ground to energize the EVAP purge solenoid valve (purge on). The EVAP purge solenoid control is pulse width modulated (PWM) or turned on and off several times a second.

Fuel Tank Pressure Sensor




The fuel tank pressure sensor measures the difference between the air pressure (or vacuum) in the fuel tank and the outside air pressure. The sensor mounts inside the left rear wheelhouse behind the liner panel.

System Operation
The EVAP canister purge PWM duty cycle varies according to the operating conditions determined by the mass air flow, the fuel trim, the engine coolant temperature, and the intake air temperature . For certain EVAP tests, the diagnostic will be disabled if the TP angle increases to above 75 percent.

The evaporative leak detection diagnostic strategy is based on applying vacuum to the EVAP system and monitoring for vacuum decay.

The fuel level sensor input to the PCM is used to determine if the fuel level in the tank is correct to run the EVAP diagnostic tests. To ensure sufficient volume in the tank to begin the various diagnostic tests, the fuel level must be between 15 percent and 85 percent.

The PCM monitors the fuel tank pressure/vacuum level via the fuel tank pressure sensor input.

Results of Incorrect Operation
Poor idle, stalling and poor driveability can be caused by the following:
Malfunctioning purge solenoid
Damaged canister
Hoses/lines split, cracked and/or not connected properly
Evidence of fuel loss or fuel vapor odor can be caused by the following:
Liquid fuel leaking from the fuel lines
Cracked or damaged canister
Inoperative canister control valve
Vacuum hoses that are:
Disconnected
Incorrectly routed
Kinked
Deteriorated
Damaged
The evaporative leak detection diagnostic strategy is based on applying vacuum to the EVAP system and monitoring vacuum decay.

The PCM monitors vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP purge solenoid and the EVAP vent solenoid are turned on, allowing engine vacuum to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved, the EVAP purge solenoid is turned off, sealing the system. A leak is detected by monitoring for a decrease in vacuum level over a given time period, all other variables remaining constant. A small leak in the system causes DTC P0442 to be set.

If the desired vacuum level cannot be achieved in the test described above, a large leak or a faulty EVAP purge solenoid is indicated. This can be caused by the following conditions:

Disconnected or faulty fuel tank pressure sensor
Missing or faulty fuel cap
Disconnected, damaged, pinched, or blocked EVAP purge line
Disconnected or damaged EVAP vent hose
Disconnected, damaged, pinched, or blocked fuel tank vapor line
Disconnected or faulty EVAP canister solenoid
Disconnected or faulty EVAP vent solenoid
Open ignition feed circuit to the EVAP vent or purge solenoid
Damaged EVAP canister
Any of the above conditions sets DTC P0440.

A restricted or blocked EVAP canister vent path is detected by drawing vacuum into the EVAP system. The PCM turns off the EVAP vent solenoid and the EVAP purge solenoid (EVAP vent solenoid Open, EVAP purge PWM 0 percent). The PCM monitors the fuel tank pressure sensor input. With the EVAP vent solenoid open, any vacuum in the system should decrease quickly unless the vent is blocked. A blockage is caused by the following conditions:

Faulty EVAP vent solenoid (stuck closed)
Plugged, kinked, or pinched vent hose
Shorted EVAP vent solenoid driver circuit
Plugged evaporative canister
If any of the above conditions are present, DTC P0446 sets.

The PCM checks for conditions that cause the EVAP system to purge continuously by commanding the EVAP vent solenoid on and the EVAP purge solenoid off (EVAP vent solenoid CLOSED, EVAP purge PWM 0 percent). If fuel tank pressure level increases during the test, a continuous purge flow condition is indicated. This can be caused by the following conditions:

EVAP purge solenoid leaking
EVAP purge and engine vacuum source lines switched at the EVAP purge solenoid
EVAP purge solenoid driver circuit grounded
If any of the above conditions are present, DTC P1441 sets.

Refer to the appropriate DTCs for further diagnostic procedures regarding the EVAP system.

Visual Check of Evaporative Emission Canister
Cracked or damaged, replace the canister.
Fuel leaking from the canister, replace the canister and check the lines and the line routing.

--------------------------------------------------------------------------------
Document ID# 429828
1999 Chevrolet/Geo Corvette

 

thanks, sounds like i will find someone to knock out the codes for me..where did you run the rubber line? near the back end?

 

WHY hack the car up for this? By the time you go through all this and pay someone to reprogram the computer, you could have fixed it correctly.

 

Because its a bunch of unnecessary crap cluttering the engine bay and dumping other than fresh air into your intake.

 

Dumping GAS FUMES into the intake to get BURNED. You payed for the fuel, why not use it AND with the engine covers on, you can't see the plumbing (what little there is for this).

 

Yes, with the evap system you're correct, I removed that more for the aesthetic reasons in the engine bay. The PCV system on the other hand was removed and vented to the atmosphere for both aesthetic and and performance reasons. As was the AIR system, but to each his own. Either way, the EVAP system is purely an emissions requirement and does not effect the performance.

 

So leave it be then since neither do any harm and help the air the HUMANS breath.

 

Right. Anyway, to the original poster, yes you can remove it, no it doesnt affect anything performance wise, yes you'll probably need someone to go in and tune out the code its going to trigger (resister didnt work for me), and no you're not hacking up your car by removing it.

 

Tell that to the next guy that has to try to pass emissions with it. My last Vette was like this, took a lot of research to figure out the Redneck engineering of the last owner..

 

how could removing this affect emissions? dont they just stick a tube in the exhaust? its there because they cannot dump fumes off into the air.. i dont think it will affect passing emissions..? cats will affect emissions removing the A.I.R. system will affect emissions passing but i dont the evap has anyhting to do with it.

 

please... get a grip ..your daily activities are throwing out more bad emissions than my car i drive 5 months a year concerning a evap canister's purpose

 

there is NOTHING that is hacked up about my car.. i removed the A.I.R. system when i did headers... its in the same ballpark and its not hacked

 

Hahaha....redneck engineering....spoken like someone who has never had the valve covers off their car. Also sounds like you should have been a bit more thorough in your research prior to buying your car.