That's the charcoal canister. It is connected to the fuel system. There is a hose coming out the bottom. The hose out the bottom just plugs into the frame rail underneath it.
generic description from the internet:
Quote:
The vapor canister is a container full of charcoal, and it absorbs vapors from the fuel tank, and depending on the vehicle, vapors from the carburetor, and other fuel handling items.
Then, after the engine has warmed up, and is running down the road, the computer, or some other item designed to control it, will open a valve and draw air through that canister, drawing those evaporation fumes into the engine, and burning them with the air/fuel mixture.
The purpose is to eliminate those fumes from being released into the atmosphere.
Some possible problems with not replacing it are...those evaporation fumes will be vented out under the vehicle, and you may smell strong gasoline fumes. Very slight possibility it could catch on fire, but not real likely.
Also, when the ECM,(computer) tells the valve to open and purge that canister, it will be sucking unfiltered air into the engine. On good clean paved roads, not too much dirt would be drawn in, but if you drive on dirt roads, you should at least find and plug that hose.
Depending on your vehicle, the absence of that canister can be detected by the computer when it performs a purge command, or a system self-test, and it may store an emissions code, and turn a light on in the instrument cluster.
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and another that explains the purpose
Quote:
EVAPORATIVE CONTROLS
Gasoline evaporates quite easily. In the past, these evaporative emissions were vented into the atmosphere. 20% of all HC emissions from the automobile are from the gas tank. In 1970 legislation was passed, prohibiting venting of gas tank fumes into the atmosphere. An evaporative control system was developed to eliminate this source of pollution. The function of the fuel evaporative control system is to trap and store evaporative emissions from the gas tank and carburetor. A charcoal canister is used to trap the fuel vapors. The fuel vapors adhere to the charcoal, until the engine is started, and engine vacuum can be used to draw the vapors into the engine, so that they can be burned along with the fuel/air mixture. This system requires the use of a sealed gas tank filler cap. This cap is so important to the operation of the system, that a test of the cap is now being integrated into many state emission inspection programs. Pre-1970 cars released fuel vapors into the atmosphere through the use of a vented gas cap. Today with the use of sealed caps, redesigned gas tanks are used. The tank has to have the space for the vapors to collect so that they can then be vented to the charcoal canister. A purge valve is used to control the vapor flow into the engine. The purge valve is operated by engine vacuum. One common problem with this system is that the purge valve goes bad and engine vacuum draws fuel directly into the intake system. This enriches the fuel mixture and will foul the spark plugs. Most charcoal canisters have a filter that should be replaced periodically. This system should be checked when fuel mileage drops.
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2015 BRZ Limited 6MT
92 Ebony LS-L ECUtune Stage2av1, Z32 MAF, 370cc injectors, TomsSVX intake, BontragerWorks 22mm RSB #003, HID Hi and Lo beams, OT endlink and bushing mods, PWR Aluminum radiator, Harvey's QC shift kit, 2.5" flowmaster 80 exhaust, 17" Michelin Pilot Sport A/S, Poly sway bar bushings, Slotted Bradi rotors, AFBeefcake powdercoated calipers, 97 grill, and a huge set of air horns. 300,000 miles and counting
92 Ebony LS-L. ecutune stage1v4, motorsport 1pc pulley. Garage Queen - sold to Dad in upstate NY 155,000 miles
19 Subaru Ascent Premium - -Hers !.
89 DL 4x4 little red wagon - a.k.a. The immortal suby. 275k R.I.P.
Last edited by immortal_suby; 09-15-2007 at 02:47 PM.
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