CODE 172

[MBopp94SHO]

Hey all

My 94 SHO ATX 112k is giving me ONLY Code 172
Would that indicate simply that the Rear 02 is going bad? I have some oil in plug wells, but I cleaned it almost all out.
I believe they are originals, could just be time.
Likely to the get Bosch, what's 3.2 part #s?

Maintanance wise, everything except the Valve adjustment with shims and plug tube seals has been done back in the 80k

 

[JoeHoe_SHO]

Change both o2 sensors...

 

[Mr Anonymous]

The easiest way to check an O2 sensor when only one is throwing a code is to swap them. If you swap them and the front shows lean, then you know it's the sensor (and replacing both would be a good idea).

If you still get a 172, then chances are you are having a true lean condition in the rear bank and you'll want to do a little further investigating to isolate the cause (usually a vacuum leak at the intake-to-head gasket).

The P/N for Bosch ATX O2 sensors is 15716 ($40-$50/ea depending on where you get them).

 

[sdpatt]

If they are old enough for one to fail the other can't be helping your engine's performance or mileage either. Replace them both with the Bosch 15716.

<small>[ September 03, 2003, 10:36 PM: Message edited by: sdpatt ]</small>

 

[wood_e]

I got a 172 this weekend, but my mileage is excellent! I get nearly 27 on the highway... shrug