I consistantly get a P1456 (Evap Emission Control System Leak Detected - Fuel tank system). At first I thought I didn't tighten the gas cap, but the code keeps coming back after I reset.

Is this common with AP2s?

This is covered under warranty, but it is a PITA to go to the dealer (the only one I trust is 35 miles away).

 

This would be covered under warranty.

 

I guess '04s aren't immuned to bum gas caps or even bad filler necks. At least 3 solid clicks on the gas cap, right?

 

Lately about 12 clicks.

 

 

Start with a new gas cap, then target the filler neck. Warranty should cover both.

 

I've have the same issue. Problem is, the cap will click but it's not 'seated' It hangs up or binds before it screws all the way down. Short of a new filler neck, lube the threads on the cap. I carry motor oil in my trunk a little on the threads works great. WD40 is good. Latley I've been using gas. You know those drips that we try and keep off our paint after we fill up? Let it drip on the threads! The Key is to screw the cap down like closing a jar. Grab the cap around the outer edge for grip. When the cap is all the way down It will stop. Then 'click' it 3 times. I understand there is TSB for Deformed filler neck. I thought Honda would have resolved this by now. Finally, To me metal against plastic is a recipe for wear. That's why I'm convinced a lot of our soft top wear holes are a result of this. Sorry to be long winded, hope this helps.

 

You said you "reset" the code...if u just disconnect the battery terminal the cell will come back. You have to take your car to Autozone and they can clear the code for you if it just a loose gas cap. That's what I had to do to clear my wife car cell when I didn't tight the gas cap.

 

This is not correct. You can reset an S2000 (pre-'06 anyway) ECU by disconnecting the battery or, even better, just removing the BACK UP fuse for a few seconds. The CEL will come back on ONLY if the condition persists.
People have been clearing codes out of S2000 ECUs for years doing it this way.