[Jack1953]

I am at a point with my beloved 1998 Accord where I'm not sure what to do next. With 236,000 miles it's been a great car and it still is. My goal was 300,000 but I'm not sure we'll make it there.

It definitely needs a new cat but I'm doing these one at a time so here I would like to talk about the P1456 code. My registration deadline is only a few days away so I may be driving illegally, (don't tell anyone).

At the emissions test I got the P0420 and the P1457. I have an OBDII scanner so I've been doing some test driving. After reading the forums I decided to replace the canister vent shut valve. It worked! No more P1457! I was just about to go to a well respected muffler shop that will put a new cat on for $200 cash when a new code popped up on my scanner... the P1456. I've never had this one before.

After some reading I put on a new gas cap, the old one did have some broken plastic teeth in it and I'm going out now to do my drive cycles and see if I can get the damn tests to run. This test can take several days as you know so I will post back the result here. Any suggestions are welcome and appreciated. I hate to see a perfectly good and strong car totaled over a P1456 error.

 

[Jack1953]

Resolved it!

Thanks for reading my post. I took it out for the test drive(s) after replacing the fuel cap and as soon as the testing finished the P1456 error came back. I was very disappointed because I've been reading the many possible problems that can cause this error and the seemingly complex diagnostics.

Then I read that someone recommended tightening the cap 7 or 8 clicks... I had only tightened it 3 or 4. So I ran the test again after tightening the cap 8 clicks and the P1456 did not return.

Strangely I also had the P0420 code and after the last test drive that code hasn't returned either. I doubt that the gas cap could be related to catalyst efficiency but who cares..... I hurried down to the emissions test and it passed!

I may still make it to 300K! Knock on wood. :salue: