engine code 172, 173

amajamark8

Registered
Hey Guys,

I have had an intermittant CE light on my '94, seems like when it is raining (or after I washed the car). It fluctuates on and off. I know there is a brick sized module in front of the radiator, I don't know what it is, but it does get wet. I scanned the computer and got two memory codes:


#172 - Lack of heated oxygen sensor switches indicate lean bank 1

#173 - Lack of heated oxygen sensor switches indicate rich bank 1


Any ideas what the codes mean and if it could be related to the "brick" and it getting wet (maybe bad connection or something?)

Thanks in advance.

Jon
 
RE: engine code 172, 173

My guess would be something is wrong with your oxygen sensor, which is in the exhaust. Perhaps it's burnt out, or there is a crack in the insulation so when the water contacts one, it is shorting.
 
RE: engine code 172, 173

I am getting these codes on my 94 now. Rich and Lean at the same time! Did you ever get yours fixed?

David
 
RE: engine code 172, 173

It happened a couple of times, but I haven't driven the car since the end of May...blown tranny, no time or cash to repair.:( I've got to get that taken care of pretty soon...

amajamark8
 
RE: engine code 172, 173

If I get both rich and lean codes from the same bank, it's almost always (except for a few bizarre cases) the O2 sensor. The "other" Frank is right. The outer shell is probably cracked and allowing water entry. Keep in mind, Bank 1 is the passenger side.
 
RE: engine code 172, 173

They just thread into the exhaust like an oversized spark plug. That's not the point, though. Bank 1 is in a very awkward place-- you can't swing a normal wrench in that area. You need an O2 crowsfoot wrench, which can be found at any auto supply store, a 6-8" extension, a lot of WD40 and even more profanity.

One thing you didn't mention in your first post: a really severe ignition miss in one or two cylinders on the same bank will cause both rich and lean codes on that single bank. How does your car run in the rain?
 
RE: engine code 172, 173

Like I said before, I haven't driven the car in a long while...I don't really remember. Probably not great, but the first time it threw that code was right after I washed it and I was thinking I got something wet.
 
RE: engine code 172, 173

[div class="dcquote"][strong]Quote[/strong]
They just thread into the exhaust like an oversized spark plug. That's not the point, though. Bank 1 is in a very awkward place-- you can't swing a normal wrench in that area. You need an O2 crowsfoot wrench, which can be found at any auto supply store, a 6-8" extension, a lot of WD40 and even more profanity.One thing you didn't mention in your first post: a really severe ignition miss in one or two cylinders on the same bank will cause both rich and lean codes on that single bank. How does your car run in the rain?
[/div]

It doesn't seem to matter - wet or dry.

A severe ignition miss - so that could be a coil pack or wires or, what else??? plugs I guess... what else?



94 Mark VIII, Black / Black
dynoed at 247.5hp / 259.7ft-lb!
 
Back
Top