Question

1999 Nissan Altima with P1491 code, where is the bypass valve cut switch located?

Answer 1

Here is a diagram, the vacuum cut valve is located under the car,next to the charcoal canister. There are 2 vacuum lines to it and one electrical plug. Make sure to check the hoses for cracks or any holes rusted through the steel lines.

Answer 2

P1491 NISSAN - Vacuum Cut Valve Bypass Valve

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