Well I'd like to update this thread as the car is now FIXED!

I threw in the white towel and took to the car to the dealership. They checked all solenoid functions and no issues showed up. So they went ahead and did a smoke test. The brand new Dorman bypass solenoid I had installed was cracked and leaking vacuum right out of the box. Keep in mind that was the only non-OEM part I installed. They put a new one, few days later all codes were good and nothing pending, and I went ahead and passed emissions. Attached is a picture of the POS, it was also leaking out a small crack on the other side as well.

 

cuda6pk, JimBlake, RedBull and et al,

I have the P1457 code and am at my wits end as well (entire history here, https://www.hondaaccordforum.com/for...-accord-55916/)

Summary for you:
1. Earlier this summer, the car did not start on a very hot day. After cranking the car for a few seconds, the car started and there was an odd smell (it was mixture of smells mostly gasoline). Car stopped as i was trying to park. On the highway, in D4, right lane, there was no response when I pressed the gas pedal. Pulled the car over. After a couple of seconds, the car started fine. The car hesitating or failing to start occured over a couple of days. I removed fuse 15 for the fuel pump and the car seemed to start fine after.

2. I took the car to my trusted mechanic John, who cleaned the throttle body and IAC, maybe did not do an ILP.

3. I brought the car back home, it had a very high idle 2000RPM, when I shifted gears, i could see the RPM shoot up. 2 days later (maybe 6 trips), P1457 showed up. I confused myself thinking it was the gas cap, i tightened the gas cap and waited a few more days...the light stayed on.

4. I drove the car for nearly 4 weeks and decided to go see the mechanic. 2 codes P1457 and P0420. The O2 sensors were switching in voltages correctly. John performed a smoke test and did not see any obvious leaks (the vent at the gas tank was releasing smoking, I am thinking that is what it is supposed to do).

5. Next, we tested the voltages on each solenoid under the hood and under the body. We found the purge solenoid (is this the same as bypass solenoid, that is the part that was replaced) was not engaging when the pressure was greater than 15lbs. Less than 15lbs it was always engaging. We thought we had found the root cause.

6. I ordered genuine honda purge solenoid from hondaautomotiveparts.com and went back this past tuesday with the part. We installed the part. Very interestingly, during the install, John removed the 2-way valve and it was leaking gasoline (ofcourse, doesnt it have both vaccum and gas lines?). I also had an ATF leak (cooling line to the radiator). We bought an aftermarket cooler from AAP and bypassed the radiator and installed a transmission cooler.

ofcourse, I didnt have the benefit of cuda6pk's experience, we didnt check the integrity of the OEM part or for that matter do any post-installation testing (checking voltages or a smoke test). I am taking the car back on tuesday to get these done.

7. On Friday morning, when I was stopped at a traffic light, the car shut down in D4 and with my foot on brakes. I did notice that the RPM on D4 was between 800-900RPM. I turned the key and was not able to reproduce the issue. I took the car to the dealership (thinking it may have something to do with ignition coil and had them check/inspect/fix ignition interlock recall that had never been addressed). I also got an oil change done (they used 5W20 - first time on the car since purchasing it).

8. In the evening, I started the car and shifted to reverse and the car shut down. I turned the key again, it cranked and started. On the way back home, the CEL came back on. I drove to autozone and it had 2 codes, P1457 and P1739.

So far, I have installed an aftermarket gas cap (Autozone), Honda Purge Solenoid and never fill gasoline more than half way. At this moment, I am thinking the only other element left is the purge canister valve.

Any thoughts? How can I tell the charcoal canister is bad, saturated or working fine?