Help w/diagnosis
 

So I went to an autozone where they plugged in a code reader (my check engine light came on wednesday) and came up with oxygen sensor. Course I think my truck has two. I called my hometown mechanic and he said that while he could price putting in a new O2 sensor, he couldn't be sure that that was the actual problem, but that rather it might be something that was beyond what the sensors part of the system could correct for (nice to have helpful mechanic).

Now if I can't solve it myself, I will probably take it to my guy when i go back for a visit to ohio in two weeks (haven't been here long enough to go thought finding a trustworth shop). But i just thought I'd put it out here and see if you all had any tips and what I might check in the system.

Truck still seems to run alright, though gas mileage appears to be down (lots of city driving of late tho.)

thanks,
Ian

Ian,

Did they say front or rear 02 sensor? If front, it is a tad bit more difficult to change given the location (the rear one is ridiculously easy), but easy to do.

I say change out the front one if you are 100% it is the front one.

http://4runners.org/articles/02sensor/

bob

the Code reader at autozone just said o2 sensor. not real informative. I suppose that if I take it to a dealer that may have more sophisticated diagnostics equipment that will tell me which one it is, does that seems likely?

As I mentioned, my hometown guy said the O2 reading could just be s symptom of some other malfunction. I suppose, again, that a local stealership might be able help me pinpoint the problem, than I can determine if I can tackle it myself.

*note to self; start new thread asking about the best dealer service departments in the DC/Baltimore area....

Do you remember the code number?

It will tell you if it is #1 (front) or #2 (rear)

I can look it up for you if you have the code

Have to check
 

I may have to go back, I don't recall a number on the little screen, but then the guy didn't leave it plugged in very long.

Sure hope its the back one....

Definately get the code number first!
Very important to have the actual number for any diagnosis.
Take it back and have em read it again if you have any doubts.

Here are some #'s to look for (97 3.4)

Sensor #1.........prob:....................poss. cause:
P0130...........Malfunction..........sensor or fuel trim problem
P0133...........slow response...............sensor
P0135...........malfunction............open/short in heater circ, sensor, ecm

Sensor #2
P0136............malfunction............sensor
P0141............malfunction............open/short in heater circ, sensor, ecm


We change a lot more #2 sensors on the GM trucks at work