I have been checking out the emissions control systems on my car trying to fix poor idle and running.
There is a sensor on the air cleaner of my '86 SE w/4sp. There are two wires that run to the sensor...one is brown and one is red.
HERE ARE MY QUESTIONS....WHAT IS SENSOR FOR?
WHAT PURPOSE DOES IT SERVE? SHOULD THE WIRES TO THE PLUG BE HOT? HOT WITH KEY ON? HOT WITH ENGINE RUNNING? THANKS

I dont have a manual in front of me, but Im almost certain its the ambient air temp sensor - tells the ECM the intake air temp.

yes, that is the air temp sener. if its never been replaced, and your having running problems, it is a good one to replace. that and the water temp sensor by the thermostat housing are the ones to check when having cold running problems

ok....AMBIENT AIR SENSOR. kNOW APPROX COST? ALSO, ARE WIRES HOT AND WHEN?

i believe they should NOT be hot.

------------------

Here's a schematic of the MAT sensor....
http://www.syty.org/old/d&e-code23.html

You can check the resistance of the MAT sensor against the values in the table.

If you disconnect the connector to the MAT sensor, you should measure about 5 VDC at the wires when the ignition switch is ON.

Thanks, Mark, schematic will help tremendously. BTW, where did the thread comefrom. Is the information for the other codes as detailed as the one for the MAT?