CEL on Mrs. Poopypants' car

[Mr. Poopypants]

OK, so her CEL came on and I went to get the code read at Advance Autoparts. The code was P1491 - Vacuum Cut Valve Bypass Valve.Her car is a 2001 Nissan Sentra GXE. I've poked around and cannot find out what part needs replaced. Can anyone shed some light on what might need replaced without me ripping the entire engine compartment to bits???

[joatmon]

some sort of emissions control thing I guess, but other than that all I can suggest is find a Nissan forum and ask them.

[damronjr]

Sounds similar to the VSV on our Vibes. I had a similar CEL b/c o f a CAI install where I reconnected the VSV backwards. From the sounds of it it is a bad valve, though. Look for one around the intake area.

[jwalcik]

not sentra-centric, but i bet somebody here can help.

[Mr. Poopypants]

Here is something I found, looks like I need a Chilton's for her car:The vacuum cut valve and vacuum cut valve bypass valve are instaled in parallel on the EVAP purge line between the fuel tank and the EVAP canister. The vacuum cut valve prevents the intake manifold vacuum from being applied to the fuel tank.The vacuum cut valve bypass valve is a solenoid type valve and generally remains closed. It opens only for onboard diagnosis.The vacuum cut valve bypass valve responds to signals from the ECM. When the ECM sends an ON (ground) signal, the valve is opened. The vacuum cut valve is then bypassed to apply intake manifold vacuum to the fuel tank....Malfunction is detected when vacuum cut valve bypass valve does not operate properly....Possible causes:1. Vacuum cut valve bypass valve2. Vacuum cut valve3. Bypass hoses for clogging4. EVAP control sytem pressure sensor and circuit5. EVAP canister vent control valve6. Hose between fuel tank and vacuum cut valve clogged7. Hose between vacuum cut valve and EVAP canister clogged8. Evap canister9. Evap purge port of fuel tank for clogging