Question

2002 Nissan Frontier Crew Cab SE 3.3L V6 with engine code P1491. What does this code mean?

Answer 1

https://www.autocodes.com/p1491_nissan.html

 

If the EVAP canister is OK, and there are no other visual damage to the EVAP system (e.g. loose or broken hoses), replacing the vacuum cut valve bypass valve takes care of the problem.

 

Possible causes

- Vacuum cut valve bypass valve

- Vacuum cut valve

- Bypass hoses for clogging

- EVAP control system pressure sensor and circuit

- EVAP canister vent control valve

- Hose between fuel tank and vacuum cut valve clogged

- Hose between vacuum cut valve and EVAP canister clogged

- EVAP purge port of fuel tank for clogging