Where exactly will I find this black box? Do I get to it from under the car or through the trunk?

I’ll have to check that out too.

Raist

 

Yeah my wife wants me to get a locking cap anyway in case someone pries open my cover. There have been a lot of gas thefts in most of the towns in this area. I might just try one of those for the heck of it anyway.

In some places they have punched holes in tanks of trucks and vans to drain the gas. Another time they stole gas from some vans that tote some mentally handicapped (sorry if that is not exactly the most PC way to say it) kids around, and others stole from the retirement home vehicles.

Yep, we have some real winners in the areas around here let me tell you.

Raist

 

On the vent valve there are 3 nipples. 2 of them face the same direction, one faces perpendicular. Blow air through the perpendicular on and make sure that air flows out the other 2 nipples. Next cap off the bottom nipple (of the two facing the same direction) and attach a vacuum pump on the perpendicular nipple. Apply 12 volts to the vent valve. Make sure vacuum is maintained. Resistance should be 17-21 Ohms between those terminals.

 

Thanks.

I see what you mean in the service manual. Gives exact instructions on checking the ERG.
It helps to get a lot of posts when it comes to this stuff. It makes it a little easier to look up in the manual.


Raist

 

I've been having trouble pumping gas with my Evo. I feel it is due to the evap canister or the solenoid going bad as well. Anyone know if a regular lancer shares the same design?

 

There isn't a "EVAP Sensor", EVAP is monitored by the PCM and is only tested periodically. On most cars the Test is completed by closing the EVAP Canister Vent(Vent Valve) and opening the the EVAP purge Solenoid. This allows Vacuum to be applied to the system to test for leaks. If vacuum is held for a pre-determined amount of time the system is good(no check engine light), if the system loses vacuum slowly the check engine light will illuminate with a small leak code, if vacuum is lost quickly you will get a large leak code.

Most common problem for a small leak is typically the gas cap. you will NOT be able to identify a bad cap by looking at it. If you get a small leak code pick up a cap at you local parts store or dealer, cheap gamble $10-$20.

If you are still getting a code the second most common problem is the Canister Vent Valve Can get rusted open(normal position). A bad Vent Valve can throw both small and and large leak codes, different makes of cars will give different codes.

For the person having problems filling the tank. A vent valve that is stuck closed could be the cause or also a bad charcoal canister if it has ever been filled with gas do to filling with the car running and/or topping the vehicle off to the very top. It is very important with newer cars to just let the pump stop itself and leave it alone. that extra $.40 isn't going to make that much difference.

Hope this helps.

 

There's three different codes possible: P0442 small leak, P0455 gross leak and P0456 very small leak. I'd think knowing which one you have would be helpful. Gross leak probably means a hose fell off.

 

barneyb,

Knowing the code is always helpful but, only gives you a starting point. It is possible to get a gross leak code for a missing gas cap on some cars or if the cap is extremely loose. most often gas cap will throw a small or very small leak code but, we all have those moments when we rush at the gas station.

My preferred method to test an Evap system is to smoke the system but, most people don't have the equipment to do this on their own. Also, about 90% of the smoke tests I do end when I find a vent valve that will not close when power is applied to it.

Lastly, a proper diagnostic procedure always starts with a thorough visual inspection. This would tip you off to a loose hose or disconnected electrical connector. This would be most suspect if another component was serviced that required removal of EVAP components to complete the repair. i.e. fuel pump, intake manifold, etc.

 

These days the fuel system at the tank is more complicated than the engine. It sounds like you work on this stuff and everyone is saying there is no sensor back there. Well, there is a sensor, the fuel tank differential pressure sensor. What does that do?

 

Ive been gettin the P0441 code, replaced gas cap, replaced purge solenoid at the throttle body, cleaned the the filter and box under the rear bumper. Cleared the codes a dozen of times and the cel keeps coming back on everytime... What to do next? Any help would be apppreciated, just really annoyed at the cel light on. Thanks

 

The above advice is probably the best - get it smoked. As these car age I expect we will be seeing filler tubes rusting out.