Hrddrvs

I have a 2001 Civic Sedan and have the code p1456.I replaced the gas cap(OEM) and it is not the problem.When I go to get gas there is no pressure when I remove the gas cap.Is the fuel fill neck one piece or is there a gasket somewhere on the neck?I want to eliminate the neck as a possibility.I will check hoses from the neck to tank and see if there are any leaks.I would like to eliminate the fuel fill neck as a possibility but I read somewhere the neck is 2 pieces of metal with a gasket but cant find the info anywhere.There is no rust present on the entire vehicle.Please help with any info.Thank you.

GolNat

iTrader: (7)

Looks like 2 piece. Pic may help:



There is the EVAP canister that may be causing an issue. There is also a vent shut valve.

ezone

A restricted purge solenoid can cause the code too.

Hrddrvs

Is the purge valve solenoid the same as a vent shut valve?Does anyone have the description of the pic by numbers?I sincerely appreciate the help.Thanks.

ezone

There are 3 individual electric valves in the EVAP system.

Purge is on the intake manifold, the CVS and BPS are underneath the car on the canister.







CVS is #11 (canister vent shut)
BPS is #15 (module, fuel vent)




Purge solenoid is #8 below





There's a lot more to the system than those, they are not the only possible cause of any code....but CVS and Purge do fail regularly.

Hrddrvs

What does the BPS do?When I get fuel. and unscrew the cap,I never hear a hissing sound from built up pressure.I have two other vehicles and they both make the pressure release sound(hissing)when I remove the gas cap.Is the 2001 civic designed not to build pressure?I assume it should build some pressure.Also,I replaced the CVS with a new OEM.It's been ruled out.

ezone

Not so much as a design, but it is not a requirement.

Do you ever smell gas fumes when the car is parked? (helps if you park in a closed space, garage)



BPS is the valve used to separate the tank section from the canister section during the computer self testing of the EVAP system.

Hrddrvs

I have'nt noticed any gas smell when parked.I'm gonna get the BPS and the Purge Solenoid.Is the Tank Pressure Sensor something I should look at also?There is a Pick Your Part nearby and a lot of times I find parts that look recently replaced(new) and I can get those for about $6 each this weekend because they have a 50% off parts sale every month.They have quite a few 2001-2005 civics.I hope to get lucky. and just replace them all.Is the BPS pretty easy to remove/install?Why do some hoses related to different valves/solenoids not attached with hose clamps?Does that mean they dont ever have pressure?Thanks again.

ezone

If you had a scanner and a way to actually diagnose, then being able to read the values would be worthwhile.
If you just want to swap out parts, then I would not bother with that one.

I dunno, I rarely ever have to touch one of those.

Get this one from a 04-05 car.
The early ones 01-03 have problems
^HINT^

I can't answer that either. You need to ask the engineers LOL
The vapor pressure or vacuum inside a gas tank is pretty minimal. Not enough to cause unclamped hoses to blow off IMO.

Hrddrvs

Thanks ezone for the info and advice.Will the check light reset itself after repairs are made or do I have to reset it?

ezone

It's a lot faster to clear the codes and see if it comes back on rather than wait for the system to pass the self test like 3 times or something and HOPE you got it right.

Hrddrvs

OK,sounds good.Thanks again and I will post results.

Hrddrvs

So I replaced purge and bps.The code came back again.I just started noticing a light smell of gas from under the passenger side under the vehicle.The cabin has absolutely no smell of gas,only outside.Is there anything I should look at or possible common problems this could be?I checked hoses but they look good.Any help is appreciated.Thanks.

ezone

CVS valve rusted away?
This is what I see as the most common failure but it usually causes code P1457.

Here's a pic of one leaking, after applying about 1PSI of air pressure and a liberal amount of soap and water on an otherwise sealed charcoal canister removed from the car:






I also see a lot of cars with rodent damage, critters will chew on almost anything and it can get expensive. I've replaced complete gas tanks because critters ate through molded-in tubing, I've replaced plastic fuel lines that have been chewed through, repaired tons of wiring all over the cars, and more.

Hrddrvs

There's no critters around here that I have ever seen or known about.I also replaced the CVS valve with a new one.I find it a odd that I smell the gas under the passenger side but not the driver side.What does it take to saturate the canister?I had an issue a few weeks ago where the engine would'nt start after I stopped at 7 Eleven.The gas gauge said about 1/4 full.I ended up putting gas in and then it started right away.After that incident,the engine light came on about 20 miles later.Could I have ruined something by cranking it over without gas?I never top off the tank either so I dont think that's a possibility.

ezone

Mice, rabbits, squirrels, chipmunks? Any animal that gnaws can chew this stuff.

We had a salesman show a new truck to a customer, when they opened the hood to see the engine they were greeted by a rabbit happily munching on injector wiring.
Good times!

If you can SMELL gasoline then the code is not lying, you have leakage somewhere in the tank or vapor system.
Probably not a pressurized liquid fuel leak as those usually do not cause codes.

Keep in mind it could be caused by your repair work too, as you only mentioned it after you worked on it. Did you not get the large hose clicked onto the top of the canister all the way?

Figuring out where the actual leak is can sometimes be quite tricky even when one has all the tools of the trade at hand.
Overfilling the tank is the usual cause.
No, some people run out of gas rather frequently in these cars without hurting anything, the fuel pumps are quite reliable.

Hrddrvs

I checked all hoses and they are all properly connected.I dont know if the gas smell was there before any work done.I never checked for the smell.I now noticed it comes from the driver side also.I still have to check the fill pipe.I got a feeling this is going to be a waskally wabbit to fix.How often does the canister go bad and if it is bad,would it give a code p1456?Also,what is your opinion on this timing belt kit?http://www.ebay.com/itm/AISIN-Water-Pump-Timing-Belt-Mechanics-Kit-961-72003-Honda-Civic-1-7L-01-05-/270912244367?fits=Year%3A2001%7CMake%3AHonda%7CModel%3ACivic&hash=item3f13a0ca8f&vxp=mtr

RIPSAW

.......Do that pay you more for this kind of work?

ezone

Smoke machine is one way, another might be to pressurize (LOW pressure) the system then spray it all down with soapy water then look for bubbles.


I've only replaced canister for having the CVS screws stuck. Never really seen a bad canister itself as a cause of any code unless it's physically broken and leaking (can't hold pressure or vacuum).
No opinion, other than I'm a fan of factory parts for the tensioner and water pump at the very least.
I think I get paid weakly.