dhoff024

The check engine just came on in my 2001 honda accord. It is a v6 2dr ex I ran the code and it was a P1457 which is EVAP Emission Control System Leak Detected (Control Canister System). I am wondering what this could be I already checked the gas cap just to see but the gas cap is fine so other than that I don't know what to check. Any help would be greatly appreciated.

sgraham01

check all the EVAP hoses for cracking or leaks. if you can't see anything, take it to a shop that has a smoke machine. they pump smoke into the system to find the leak.

dhoff024

What hoses exactly am I supposed to check? I dont know what all the EVAP hoses are and where they are located? Thanks

sgraham01

all hoses running to and from the charcoal canister. go to hondapartsnow.com and find your canister in one of the diagrams if you don't know where it is. I don't know about an 01. i have a 94.

clempot911

I know yours is a V-6, the EVAP system on that vs. a 4-Cyl may be slightly different (but the TSB I looked at didn’t differentiate, so I assume they are really the same). In any rate, here’s a write-up I did regarding this on my ‘00 Accord a while back. Hope it helps.

P1457 is caused when there is a leak detected in the EVAP emissions system. This system collects and stores fuel vapors in a special canister until conditions are met which allow them to be burned off by the engine. This is not to be confused with a P1456 fault which may happen with a loose gas cap.

Many Honda models between 1998-2004 have problems with this system because of it’s design. Honda put several of the key components in a very susceptible area – next to the driver’s side rear wheel well (at least that's the location on the Accord). When you drive in wet conditions, these components get splashed with water. Even worse, in the ‘rust belt states', the components get splashed with ice/snow melting chemicals, which are even more corrosive. With time, the water, or chemicals, corrode the exterior of the parts and work their way down into the components, and start corroding them on the inside. Once the components start to corrode on the inside it’s very likely they can short out.

Unlike many other faults which set a Check Engine Light (CEL), this is one you DO NOT want to ignore. If a component shorts out, when the Powertrain Control Module (PCM, the computer that runs the engine) tries to activate the valve/solenoid, it instead finds a dead short...which can blow the transistor controlling that output. Once that happens, there’s no fix – except a new (expensive) PCM. Unfortunately, the EVAP system ‘runs’ whenever the PCM sees that the correct conditions are present – that means that it may run several times a day on 1 vehicle, and a lot less frequently on another, it’s all based on what the conditions are. Which is to say, one vehicle may have PCM damage happen quickly, while another may not. To avoid the possibility of ruining the PCM, its best to fix the problem as soon as possible. If there is damage and you do not replace the PCM, the CEL will never go away, and in many states that means you will fail the Emissions Inspection.

Most likely, the fault is being caused by 1 or 2 components: The Canister Vent Shut Valve, or the EVAP Two-way Valve Solenoid. Depending on the situation, you may be better off dropping the EVAP canister (the rectangular plastic canister next to the driver’s side rear wheel) down to get at the components – once you unplug any hoses/connectors going to/from the canister, there is 1 bolt that holds the canister to the vehicle. Make sure you label where everything goes, and plug any hoses – there may be gasoline fumes coming from them. Note that some hoses are longer and may allow you to drop the canister with them attached.

The Canister Vent Shut Valve is mounted on the EVAP canister, has an electrical connector and a large hose connected to it. It’s attached to the canister using 2 Phillips head screws. It’s a good bet that these are very corroded. You can try spraying some rust penetrant on them and let it sit a while before attempting to remove the valve, but chances are you may strip the screw heads. If that happens, option 2 is to use a set of needle-nose locking pliers (like Vice-Grips) to clamp onto the screw heads and slowly work them out, taking your time and working the screws back & forth. If at any point the screw stops turning, STOP. Screw it back in a ways, then back out. Don't force them out - the screw threads are mounted in the plastic canister housing and can break off.

Once the valve is out you can test for a short or stuck valve by applying 12V to the terminals – make sure you check for any polarity labels on the valve. You should hear it click. But even if it does click, it may still leak/vent to the outside due to corrosion of the outer clamp assembly that holds it together. If you want to test for that you need to plug one side, apply a few PSI of pressure on the other side by using a Mityvac or something similar, and brush a soap solution around the seams. You will see it bubble around the areas that it leaks. In my opinion, for the cost and since you already have it out, replace it – it will eventually fail anyway.

The other likely component is the EVAP Two-Way Valve Solenoid. This unit is under a 2 piece cover, has 2 hoses visible going to it, and is to the side of the EVAP canister. Pry one of the covers off to get access. The hoses attach to the valve, which is probably OK, but the actual solenoid attaches opposite the hoses. The solenoid attaches to the valve using 2 screws, and attaches to the vehicle using 2 screws. There is also an electrical connector at the top. You may need to remove the valve/solenoid as an assembly to check and work on it – if so, there are 3 hoses total connected to it, make sure you plug any hoses as you remove them, and label them so you know where they go.

Once the valve is out you can test for a short or stuck valve by applying 12V to the terminals – make sure you check for any polarity labels on the valve. You should hear it click. If you do not, a replacement solenoid is available, make sure you replace the 2 o-rings that seal it to the valve body.

Re-install everything onto the car reversing your disassembly steps. If possible, reset the Check Engine Light. You should be all set.

JamesB1985

Great Reply! Very interesting.

john4153

Thank you clempot911. Here is a little additional information.

I have a 2000 Accord V6 and did the vent shut valve* replacement last weekend. It is not beyond an over-65, non-professional mechanic. Here is all I needed to do:

The hardest part was getting the car properly jacked and supported. I used the center jack point in the rear and two jack stands. For tools, you need 10mm and 12mm socket wrenches, vise-grip pliers, and a Phillips screwdriver. A 10-mm crowfoot or very short socket will be helpful. There are three bolts (10-mm head) that hold the canister to the car. There are two bolts (12-mm head) that hold a parking break cable bracket. Remove all 5 bolts. Undoing the parking brake cable bracket allows easier access to the canister. The rear-most bolt on the canister is under a cross brace. That is where the crowfoot or shortened socket comes in handy. After the bolts are removed, drop the canister down so you can access the two screws holding the shut valve in place. The screws are probably rusted. Use vise-grips (use ones with teeth on the jaws, if available) to grab the screws by the sides and get them started to turn. A little penetrating oil helped too. Of course, you need to disconnect the electrical connector, which is a typical pinch and pull connector, and the rubber connecting tube. Replace the new valve and reassemble. The valve does not come with the two mounting screws. My Honda dealer was kind enough to give them to me, including new washers.

*The correct name of the valve is as stated above. Autozone had no listing for the shut valve. It has the identical valve, same manufacturer and same Denso number, but calls it a bypass valve. I used the Honda part number and my local store was able to cross check it. The price difference was significant.

John4153

clempot911

Thanks for the additional info, it sounds like there are some subtle differences between the 4 and 6 cylinder - on mine the canister was just held by 1 bolt and I didn't have to do anything with the parking brake cable.

I actually went through the same thing at Autozone, they called the shut valve something different but by the illustration on the website it looked correct so I ordered it. As you found, it's the same part, same manufacturer, etc. but considerably less cost than what the dealer wanted. I did end up getting the other part - the 2-way valve solenoid - at the dealer, it was a wallet lightening experience but I needed it that day, not a lot of options.