'87 Monte SS aero throwing 4 codes *** need diagnostic help

[TomDisab]

I have an '87 aero coupe that's throwing these four codes: 13, 24, 41, 45. The check engine light comes on at idle, and goes off when car is warm and running. The car and engine has 2800 miles on it, not modified with 2 degrees advance timing. I cleared the codes once but they are back.
code 13, o2 sensor or circuit
code 24, vehicle speed sensor or circuit
code 41, no distributor signals to ecm, or faulty ignition module ( carbed models)
code 45, oxygen sensor or circuit - rich exhaust detected

Any idea's?

 

[fleming442]

I'd start by replacing the O2 sensor and cleaning the optical sensor on the back of the speedo.

 

[TomDisab]

I'd start by replacing the O2 sensor and cleaning the optical sensor on the back of the speedo.

Thank you for replying. I guess it does indicate an o2 sensor replacement. I am not familiar with the optical sensor on the back of the speedometer, though. Can you describe the look of it and function?

 

[fleming442]

If you pop the gauge cluster out, there's a little green or black doohickey on a single screw with 3 wires coming off it next to where the cable plugs in; that is the "eye" for the speed sensor. the 3 wires go to a translator box near the headlight switch for the ECM and cruise control. I'm assuming that it could get dusty and give a bad reading, although, most people end up gutting the cruise, anyway. I think I still have mine from the Bonneville in the gauge cluster, and might be able to get you a pic when my new phone comes in (long story; don't ask).
Mine used to get a little funny while the cruise was engaged (randomly died like it was starving for fuel at highway speed), but I never did investigate the issue.

 

[pontiacgp]

is the O2 (code 13) and Oxygen sensor (code 45) two different components?.....

 

[TomDisab]

If you pop the gauge cluster out, there's a little green or black doohickey on a single screw with 3 wires coming off it next to where the cable plugs in; that is the "eye" for the speed sensor. the 3 wires go to a translator box near the headlight switch for the ECM and cruise control. I'm assuming that it could get dusty and give a bad reading, although, most people end up gutting the cruise, anyway. I think I still have mine from the Bonneville in the gauge cluster, and might be able to get you a pic when my new phone comes in (long story; don't ask).
Mine used to get a little funny while the cruise was engaged (randomly died like it was starving for fuel at highway speed), but I never did investigate the issue.

That makes sense. I don't drive the car much but the last time I did last week the cruise control was acting funny. You may have nailed it for me. I'll try tearing it apart and cleaning it.

 

[TomDisab]

so the sensor is adjacent to the speedo? I'm looking for a patch of foil in that area? anybody got pictures?

 

[airboatgreg]

Replace the O2 sensor, erase codes and see what comes back. Fix the obvious first

 

[TomDisab]

If you pop the gauge cluster out, there's a little green or black doohickey on a single screw with 3 wires coming off it next to where the cable plugs in; that is the "eye" for the speed sensor. the 3 wires go to a translator box near the headlight switch for the ECM and cruise control. I'm assuming that it could get dusty and give a bad reading, although, most people end up gutting the cruise, anyway. I think I still have mine from the Bonneville in the gauge cluster, and might be able to get you a pic when my new phone comes in (long story; don't ask).
Mine used to get a little funny while the cruise was engaged (randomly died like it was starving for fuel at highway speed), but I never did investigate the issue.

I've got a picture of that green box you're talking about. That's the part that needs to be cleaned?

 

[pontiacgp]

I've got a picture of that green box you're talking about. That's the part that needs to be cleaned?

why not do this first...

Replace the O2 sensor, erase codes and see what comes back. Fix the obvious first