I have a 1994 Pathfinder and it recently failed emissions for high NO. The readings were as follows:
15 MPH test
HC – measured 25 with a limit of 123
CO – measured 0.0 with a limit of 0.80
NO – measured 3551 with a limit of 1367 (failed)
25 MPH test
HC – measured 25 with a limit of 115
CO ...