99 Accord LX 4cyl. 78K

Read a few threads on code P1456 but was wondering if anyone knew if this should effect the way the car runs. It seems like it wanted to stall a few times. It also been shifting a little funny, but that may just be 78K on the tranny it self. Just wanted to know if anyone else is experiencing the same problems.

 

That means your gas tank isn't airtight like it's supposed to be. P1456 is the code you'll get if you leave your gas cap loose. But there's a bunch of other things that can cause it, too. Mostly I don't think they'll screw up the way the car runs.

Maybe the EVAP line that's supposed to let gasoline vapor into your engine is letting liquid thru, that would make it run bad. But I'm not exactly sure whether that's a plausible way for the system to fail.

 

I've already checked the gas cap it was fine. I'll check it out more when I get home. I appreciate the reply, hope it nothing too serious!! Thanks

 

The Helm book has about 6 pages of stuff to check. Including some hoses over at the gas filler pipe, a couple valves, & a pressure sensor on the gas tank. Worst case I suppose is the tank itself??

 

Most common problem for P1456 is the vent solenoid that's mounted to the canister under the car. Water and crap gets into them, shorting them out. Honda stocks lots of them.
If all checks out and the solenoid is changed, but the light returns, the PCM may have been damaged from long term exposure to the shorted solenoid.

 

Canister vent-shut valve would throw P1457. That one happened to me. They're both part of the EVAP system, but P1456 is for the gas tank & P1457 is for the canister system.

 

Bad gas cap... it wasn't holding pressure. Replaced and everything's ok now. Thanks for all the inputs