A few months ago my check engine light came on. Threw a P1457 code, which refers to 8 to 10 possible problems with the EVAP system. Was 1st told to try replacing the gas cap. No luck. Then test for leak in the EVAP system. No visible defects. Smoke machine shows no leak. Smog & repair shop found and replaced a bad EVAP by-pass solenoid. Then they found the EVAP related part of the ECM was burnt out, and replaced the ECM. Then took it to the Honda dealer and after paying them for an hour of work, they were guessing that it might be a cracked manifold, but would require another couple hours of labor to determine for sure the problem. I took it home since the manifold is part of the exhaust system and not covered at all under the EVAP system's 1457 code. Each of the 7-8 times I've taken it to one of the three mechanic stores, they clear the code, I drive it home, but then the light comes back on within the next day. Additionally, I can now smell what I think is gas, fumes or exhaust (or something) when I'm in idle with the a/c or air vents open (not recycling)... even though they've confirmed no leak in the lines multiple times. It's been suggested it could be as simple as a worn wire somewhere hidden. But I can't pass smog in May and renew the reg with the check engine light coming on and throwing a code. Any ideas?

 

If it's a 1996 to 2000 model, they are prone to the fuse 15 problem, which is indeed a worn wire that cuts power to the EVAP solenoid among other things.

To check the manifold for cracks, idle the engine and have someone block the tailpipe with a rag while you listen for exhaust hissing out. Cracked manifold is obviously going to fail smog, but you're right it would not cause a 1457 code.