How to Fix a 1986 Buick Century's Mass Air Sensor

Before replacing the mass airflow sensor on a 1986 Buick Century, its advisable to suspect a cause of the failure of the mass airflow sensor. Inspect the air filter and the charging system as well as the wiring to the sensor. Check the positive crankcase ventilation, or PCV valve, for an accumulation of oil residue from blowby past the rings or valve guides. Oil on the mass airflow sensor wire will cause a malfunction or failure.

Instructions

Removal

1

Disconnect the negative side terminal on the battery with an 8 mm wrench. Unplug the mass airflow sensor.

2

Remove the bolts securing the sensor to the mounting bracket at the bottom of the sensor, using a socket and a ratchet. Loosen the air intake duct clamps where the air duct meets the air filter box and on both sides of the airflow sensor, using a flat-head screwdriver.

3

Lift the air duct off the air filter box, then pull the air duct off the sensor. Now the sensor is left in the engine side air duct. Pull the sensor out of the air duct.

Installation

4

Plug the new mass airflow sensor into the engine side air duct, making sure that the direction of airflow arrow is facing the engine.

5

Plug the loose air duct into the opposite end of the sensor and install the bent end of the air duct on the air filter housing box. Tighten all three clamps with a flat-head screwdriver.

6

Install the two bolts in the sensor-mounting bracket. Plug in the electrical connector to the mass airflow sensor. Connect the negative terminal on the battery and tighten it with a wrench.