Question

2000 Nissan Xterra, DTC-P1491.Emissions System-Mil On. TBS number 02-033, date-03/21/02. How do I repair this?

Answer 1

This code normally requires replacement of the vacuum cut bypass valve and the solenoid that operates it. Most common issue is a broken tail pipe allows the hot exhaust to melt the valve and cause the problem.

Here is a diagram of the location.

Answer 2

P1491 NISSAN - Vacuum Cut Valve Bypass Valve

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