TheSauce

I have a 1998 Honda Accord EX, 4-cylinder with 245,000 miles on it.

I recently took my car to a chain repair shop because the check engine light kept going on an off. They had ran the codes a few times before and it always showed P0401. They did the typical of making sure the gas cap was tight and even suggested I replaced the gas cap which I did but the check engine light would still come and go off. Sometimes it would stay off for a few days and other times a few weeks but when it comes on it would always be on for at least a few weeks.

This last time I took it in they said they would need to do a smoke test to determine where the leak was. After doing the smoke test, they told me I needed to have my Evap Bypass Solenoid replaced (I assume they mean Evap Bypass Solenoid Valve...the printout didn't have the word Valve) and I needed the EGR ports cleaned and possibly needed the EGR Valve replaced.

I did some searching online (which is how I stumbled on this site) and found multiple forums talking about the P0401 code being directly related to the EGR ports being clogged and maybe a bad EGR valve. However, nothing about that code that I can find online indicates anything with the Evap Bypass Solenoid and, from reading this site and others, code P1457 triggers when the Evap Bypass Solenoid is having issues but that code has never triggered. Even last week I took my card to AutoZone and had them run the codes and the only code was P0401.

I've been having doubts lately about the shop I have been taking my car to so, my question is whether it is possible for the Evap Bypass Solenoid to be bad without it triggering the P1457 code and would a smoke test have led to the conclusion that the Evap Bypass Solenoid was bad?

If the Evap Bypass Solenoid Valve does need to be replaced, is it called by a different name. I have looked at AutoZone's website and Knechts' and neither one have anything like that listed. I can find them on eBay and such but I would prefer to get it from an auto parts store.

Thanks,
Jared

lazlong

Google "OEM honda parts" for online dealers. They're usually 20-40% cheaper than the local dealer. Just input your model or VIN and it'll show the parts for car.

P0401 is EGR insufficient flow. Meaning the EGR valve and/or the EGR passage is clogged with carbon.

This is usually pretty easy to fix. Remove the EGR and clean it with carb cleaner until the plunger moves freely when you push it with your finger. Replace the gasket if necessary. Then reset the ECM/PCM by pulling the ECM/PCM fuse in the under-hood fusebox for at least 10 seconds (this needs to be done with the ignition OFF). If the code comes back, remove the airbox and clean the EGR passage with carb cleaner. It's a little hole at the edge of the throttle plate on the sidewall of the throttlebody.

EGR looks like this:


BTW: I'd fire your mechanic.

TheSauce

Thanks Laz. Just for clarification, are you thinking that I don't need to worry about the Evap Bypass Solenoid since I am not triggering the P1457 code?

Thanks,
Jared