Help! 1981 check engine light

[RayHardin]

I first replaced the O2 sensor, now I get the codes 13, 44 and 55. I find it weird that I can not get the 12 code to begin with, maybe this is a clue on what is wrong. I have a Haynes manual that doesn't help. Can someone give me some direction before I can get a shop manual? Thanks, Ray

 

[pbcanney]

reset the computer

 

[RayHardin]

I have reset the computer twice (removing the neg cable on the battery) with the same result.

 

[Hib Halverson]

I first replaced the O2 sensor, now I get the codes 13, 44 and 55. I find it weird that I can not get the 12 code to begin with, maybe this is a clue on what is wrong. I have a Haynes manual that doesn't help. Can someone give me some direction before I can get a shop manual? Thanks, Ray

Convert the Haynes manual to cat box liner. They are useless for engine controls diagnosis.

1) If you don't get a code 12, that alone may be a problem and might be related to the DTC55.

2) "resetting" the computer ain't gonna fix it.

DTC13, generally means the O2S is not working properly--either a lazy sensor or an open circuit
DTC44, is lean exhaust--means the engine is lean in closed loop
DTC55, generally requires replacement of the computer.

Note that I say on some occasions "generally". That means to properly solve these codes you need the factory service manual and its diagnostic info.

 

[RayHardin]

Thanks Hib, I'll have to wait until I get the shop manual. I found one and it should be here in a week.

 

[6880 Mike]

...Convert the Haynes manual to cat box liner...

Good advice.

 

[RayHardin]

Hib, thank you , you were correct. I got the shop manual and went through all of the tests and it was the ECM. I bought a refurbished one from M&S Express in Mass. No more check engine light and now it runs great.