420A Help with engine codes?

[QuickTalonTsi]

my bro just bought a 95 eclipse gs and it has a check engine light..i read the code and it gave me code 12, 21, 55. by any chance..anyone know what those might be it? i need to clear it before getting it smogged.

 

[ECLIPSEESPILCE]

in my resource all data a code 12 means the battery was disconnected.
21 has some thing to do with an o2 sensor but i dont know which one or why.
dtc 55 does not have any info sorry.
Have some one scan it to get more info.
If possible probe o2 wires with a volt meter an make sure is switches voltage. it should switch between under 1 volt with .5 as a center at idle.

 

[Engineblow1]

Code 55 means end of code string, to the best of my knowledge.