air charge temp sensor help

[kayzee2405]

Have a 92 cutlass supreme 3.1 check engine code 23 mat/ait sensor replaced the air charge temp sensor in the air box did I do this right is that the right sensor light still comes on

 

Symptoms...

Car runs good when first starts

Sometimes it has a slight rough idle and my girlfriend said it had about of on her 2x but hasn't for me almost did not didn't

Check engine light doesn't come on until you start stopping at red lights and anywhere idling for a couple min

But if no stops it doesn't come on

[RobertISaar]

23 is "MAT Low", which can be set by either of the wires that connect to the MAT sensor being broken/partially broken. not much else will set it since there basically has to be an excessively high resistance in the circuit for it to be happen.

 

23 will set when:

 

engine running for at least 4 minutes

vehicle is at 1MPH or less

startup coolant temp was above -31*F

MAT sensor indicates -31*F or less.

 

all conditions must be met for 10 seconds.

[kayzee2405]

Thank you so I'm thinking best way to do this would be to run new wires from computer any ideas on how to do this and where would the computer be

[RobertISaar]

i'd follow the factory test procedure as much as possible.

 

requires you to have access to the datastream though. the biggest part of it would be to do resistance checks for both wires that go to the MAT sensor, starting at the ECM plug and going all the way to the sensor. wiggle wires around, see if you can pinpoint where the bad section is, rather than replacing the entire length of the wires.

 

http://imgur.com/a/5bbnp

[mhildebrand]

I had this code pop up last year, and it turned out to be a broken wire clamp near the fire-wall that let the O2 sensor wires hit the exhaust and melted through the insulation. On my 96 i believe it is the Pink wire that carries 5v to everything.