Code Riddle

[oh_SHO]

I just checked the codes on a 93 ATX w/138K. The o2s were replaced one year ago this week. I got a check engine light Sat. on the drive home from college. This was after I DESTROYED a calivler. Yeah, I know, not much challenge but hey... Anyway the CEL light started going on and off. So I just ran the codes and got

176: HEGO sensor indicates system lean (LH)
177: HEGO sensor indicates system rich (LH)
543: Ignoring

How can it be lean and rich at the same time? Is it just a bad o2? Thanks in advance!

 

[AutoSHO]

Sounds like the Oxygen sensor is just bad and slow to respond.

 

[projectSHO89]

AutoSHO:
Sounds like the Oxygen sensor is just bad and slow to respond.

Yep.

Can't have it both ways with a good sensor.

Steve

 

[AutoSHO]

projectSHO89:

AutoSHO:
Sounds like the Oxygen sensor is just bad and slow to respond.

Yep.

Can't have it both ways with a good sensor.

Steve

Hehehe...

I think that statement applies to more than just oxygen sensors!

 

[sdpatt]

You may consider replacing both sensors as they are exposed to the same conditions. They should be replaced at the same 60,000 mile interval as the spark plugs.

 

[oh_SHO]

Ok, that is what I was thinking too. I'll replace it and see what happens. Thanks guys!