EVAP problem
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EVAP problem
I thought I had this problem fixed, but I guess not so here's a new thread....I'll try to be to the point.
CEL was on - P1457. Replaced EVAP canister and CVS valve. CEL went off for a while but came back on. Now the code is P0497. I understand this should not be related to the gas cap, but I replaced it anyway just to rule it out. No change.
CEL still on for P0497. Replaced purge valve. It's only been a few days but I feel it should've gone off by now. Both the original valves (vent and purge) tested good when I applied 12 volts to the pins. Neither one seemed to be leaking when closed and had full flow when open. I tested the new ones before installing them and they were good also.
I am now thinking that either voltage isn't getting to one of the valves (ECM or wiring problem) or there is a restriction in one of the lines leading up to the purge valve.
I am trying to understand how the bypass valve works and determine if it could be causing the code. Anyone know if the bypass valve could cause this code?
Am I right in thinking the next step is to find someone with a bi-directional scan tool to command the valves on and off to see if they are getting power?
CEL was on - P1457. Replaced EVAP canister and CVS valve. CEL went off for a while but came back on. Now the code is P0497. I understand this should not be related to the gas cap, but I replaced it anyway just to rule it out. No change.
CEL still on for P0497. Replaced purge valve. It's only been a few days but I feel it should've gone off by now. Both the original valves (vent and purge) tested good when I applied 12 volts to the pins. Neither one seemed to be leaking when closed and had full flow when open. I tested the new ones before installing them and they were good also.
I am now thinking that either voltage isn't getting to one of the valves (ECM or wiring problem) or there is a restriction in one of the lines leading up to the purge valve.
I am trying to understand how the bypass valve works and determine if it could be causing the code. Anyone know if the bypass valve could cause this code?
Am I right in thinking the next step is to find someone with a bi-directional scan tool to command the valves on and off to see if they are getting power?
Thread Starter
Registered!!
Joined: May 2018
Posts: 264
Likes: 85
From: Northern Wisconsin
Rep Power: 98 



Re: EVAP problem
It's been a couple weeks now...code never went off, but I think I found the problem.
First off, I found that the CVS valve connector was not on. So that was an obvious problem. I must have forgotten to re-connect it last time I was under there. I've connected it and erased the P0497 code. So we'll see if it comes back this time.
I am a little confused by the P0497 since the CVS valve is a normally open valve. That would mean if it's disconnected it couldn't close and then the ECU would detect a large leak. So I would've expected a P1457 or similar again. But honestly, idc....if the code never comes back I'll be happy.
First off, I found that the CVS valve connector was not on. So that was an obvious problem. I must have forgotten to re-connect it last time I was under there. I've connected it and erased the P0497 code. So we'll see if it comes back this time.
I am a little confused by the P0497 since the CVS valve is a normally open valve. That would mean if it's disconnected it couldn't close and then the ECU would detect a large leak. So I would've expected a P1457 or similar again. But honestly, idc....if the code never comes back I'll be happy.
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