Manifold Air Temperature Sensor

General Information

Info - V6 models only

1985-87 SENSOR, manifold air temp   25036751
     88 SENSOR, manifold air temp   25037225

"The sensor was reporting that the intake temp was over 150 degrees, but the ECM never set a code for it..."

Try a new sensor. The sensor can go bad but will not read out of normal range so it will not set a trouble code and cause the check engine light to come on. I just changed mine and it made a world of difference.

From FIERO OWNERS NEWSLETTER:

"Not only does it (MAT sensor) loose its accuracy, but its entire resistance range shifts in a direction to indicate the temperature of the air is higher than it actually is." --S.J. Wynman

From: Scott Backer

Testing - V6 models only

(approximate)

     F       C        OHMS 
   210     100         185   
   160      70         450
   100      38        1800
    70      20        3400
    40       4        7500
    20      -7       13500
     0     -18       25000
   -40     -40      100700

From: Scott Backer