Running Rich, SES Light with Codes 34 & 44

[blackonblack]

I have had this 83 H/O for awhile now and it has seemed to run rich ever since I had it. It is a little difficult to start when the engine is cold, but once started and running it will fire right up every time. It smells rich, and I don't think my MPG is all that good.

Last week, I got the Service Engine Soon Light and ran the codes with a paper clip. It flashed a 34 & 44. Oxygen Sensor and MAP sensor.

1, Can one of these failing lead to the other code?
2. Where is the O2 sensor located? Pax side exhaust from what I read, is it easily accessible? from the top or bottom? Any tricks or gotchas?

Thanks!

 

[Ribbedroof]

Running rich often contaminates the O2 sensor. I'd look at the MAP sensor and related wiring first, correct issues there, then replace the O2 sensor.

I believe the PCM will go full rich in the absence of a signal within it's desired operating range to prevent leaning the engine out and causing damage.

 

[fleming442]

Oxygen sensors get lazy with age, too. If it's original, I'd replace it for sure.

 

[blackonblack]

Final update and result: I started with the MAP sensor. I didn’t notice a significant change. After a couple days I went back and changed the o2 sensor.

For the guy who is researching how to best do this, it was easy to get at after removing the passenger tire. A bit of a bear coming out after 35 years...

The o2 sensor did the trick. Not running rich anymore, idling better, and doesn’t bog down when AC is on and at idle.

Thanks for the help fellas