Jeep Wrangler/YJ 1987-1995 Repair Guide

Non-Thermostatic Air Cleaner Assembly


The air cleaner assembly used on 1991-95 vehicles does not use the thermostatically controlled blend door and vacuum motor used in previous years. The air cleaner on these models is always open to ambient air.

The Single Board Engine Controller (SBEC) used in 1991-95 vehicles monitors air temperature in the intake manifold through the Manifold Air Temperature (MAT) sensor. The controller then adjusts injector pulse and ignition timing to compensate for air temperature.