premature o2 sensor failure (1 Viewer)

[anderaa13]

I've had 2 sets of o2 sensors fail right around 60,000 miles. This seems somewhat premature to me. each time the truck begins to run rough and eventually the check engine light comes on indicating a code 26(which i believe indicates a rich condition. Replacing the o2 sensors has fixed it each time. The originals were replaced under recall at very low mileage, since then they have been replaced twice. Does anyone know what can cause this?
thanks, aaron

 

[cruiserdan]

Code 25 and 26 go hand in hand. Do you have an FSM?

Code 25 mentions O2 sensors down the list a ways, code 26 does not mention O2 sensors.
The trouble chart lists 26 in the following order:

Engine ground bolt loose.
Open in E1 circuit.
Injector circuit.
Injector.
Fuel line pressure.
ECT sensor.
Compression pressure.
ECM.

I wonder if your engine harness is cooked by the EGR tube? :-\

D-

 

[anderaa13]

cruiserdan- i don't have my fsm with me right now, but i thought the 02 was one of the things indicated by 26. Even if its not, the first time they failed it went to the dealer and that is what they replaced to fix it. The second time (60k later) I did everything and it fixed it again (code was again 26 and same exact symptoms). Everything else seems normal and the wiring harness is fine (never worn through and i've re-wrapped it in the several locations). any other suggestions?

 

[cruiserdan]

Pardon this question,


Are you sure that it is a 26 as opposed to a 28?

The reason I ask is because I too had my O2's done under the S02 campaign. I had no issues when the campaign was performed. The campaign replacement was at 33,090 miles. I got a 28 at 76,578 miles and had to replace them again (out of pocket). I notice from your sig line that you have a '93. Do you also get an 83,84,85 ?
If so, you will need to replace the engine ECU. The original is an 89661-60170, it needs to be replaced by an 89661-60221, again at your expense (I had to do that too).

D-

 

[anderaa13]

what??? I remember one time i got three codes and that might have been them, they were 80 something. I do remember they were related to tcm communication. Only got them once a year or two ago. Also, I am absolutely certain it is a code 26 i get. I looked at my fsm last night, and your your are correct in that the chart does not mention an o2 sensor under code 26. A couple a pages later, however, it does give a driving pattern for codes 25,26 that will detect an open or short in the o2 sensor or circuit. Last time I got a code 26, I cleared it, performed that test, got the code again, replaced the o2 sensors, and it fixed it.
aaron