I recently rid my '99 TL of this DTR (Diagnostic Trouble Code) P1457.

The description in the manual is "Leak detected in EVAP Control System". These are the components that keep gas fumes from the tank from polluting our atmosphere.

Looking at all the components in the system (most are under the car just inboard of the left rear wheel) I didn't see any obvious leaks...lots of rubber hoses and stuff, but everything was tight and connected.

I then found TSB 03 - 001 which described this code as a result of corrosion in the EVAP bypass solenoid valve. Fair enough, NJ likes to salt the roads in winter to prevent pesky lawsuits. So I installed a new one.

The code came back.

Then spent some $$ having the dealer troubleshoot the problem. (The manual has the technician exercise the various solenoids in the system while checking to see if the system holds vacuum.) First they said "there's nothing wrong" but when I asked if they did all the tests, they admitted they didn't, and checked better...they told me there were leaks at the two way valve and the canister vent shut valve. Huh.

It was a crapshoot but I first replaced the two way valve. Gotta be it, I thought, cause the old one has gas in it and the internal diaphragm must be shot.

The code came back.

Then I replaced the EVAP control canister shut valve. Like the bypass valve of the TSB, this one is down there in the salt, open to road-water splash and dirt.

That seems to have done the trick! :hi5: No code now, for two weeks!


So even with the dealer's diagnostic time and the wasted replacement parts, I think I came out ahead...as my cost was half of the dealer's estimate to actually fix the problem.

I just wanted to relate my experiences in case someone else has this code.

 

Good job on making the dealer follow every single steps. Or else, they would've charged you and not found anything wrong.

 

i have this problem on my 2002 sentra

i dont wanna pay to change the vent control valve along with the canistor, so i just tried opening it up carefully and seeing if it was clogged or anythign

and it wasn't

but the light keeps on coming back

 

The canister is nothing more than a plastic bottle with charcoal inside. At least the Acura has a filter to keep it clean. If you opened it I hope you sealed it OK, might take some RTV Sealant...it doesn't see large pressures.

But a clogged charcoal canister would not cause a LEAK code on your Sentra. If there are any control solenoids down there, try replacing those first.

FWIW, I couldn't tell just by looking that the solenoid valves were bad. If I had the factory scan tool, I could have actuated the valves and measured pressure (or loss of pressure, as it were).

AcuraTL:

Yeah, the dealer was so surprised that I knew what the codes were and how the circuit worked, they gave me a revised troubleshooting procedure (than what was in my Helm factory manual). Knowledge is POWER!