02 Sensor, Help!

[tyfaciane]

I have a 97 4.3L CSFI.

My Haynes manual says there are 2 O2 Sensors for this model--Left Bank (left side manifold) and right bank (after the catalytic converter).

Well there are four--left side cross over pipe, right side cross over pipe, before catalytic converter and after catalytic converter.

Went to autozone and had them read the codes to me, I remember some stuff about left bank, bla, bla, bla, and I thing right bank too, bla, bla, bla. The scanner also called the Mass air flow sensor.

What are the possibilities of testing all the O2 sensors, and if any two are good, place them in the left bank and after the catalytic converter (right bank) and just calling life good? Or, does the "system" use all four of those O2 sensors?

[montels1]

why are you testing your o2 sensors? in a gm car or truck all they do is make the check enegine light come on. if your truck is running funny then its the maf.

[Old Man]

There are one each on each side of the Ypipe after the manifolds. They look for tune only and are one part number. Designated bank one and bank 2 , sensor one.
Third is before the cat and its designated bank 1 , sensor 2. Its job to to final read the overall tune and make slight adjustments and get a reading of exhaust pre-cat. Its a different number part and wont work in other positions, calibrated for where its at.
Fourth is after the cat, bank one sensor 3, it has only one job, to make sure the cat worked. Also a different part number.

02 codes dont mean and 02 has gone bad, 50/50 at best. A bad MAF reading causing the motor to go lean or go rich will be verified by the code of the 02 showing thr MAF is bad and not the 02 sensor. MAF doesnt know its going bad so it cant code that it is. Its coding only happens when its wildly off against the LFT's to TPS voltages or its having and electrical output voltage problem!!

[tyfaciane]

I have a 97 4.3L CSFI.

My Haynes manual says there are 2 O2 Sensors for this model--Left Bank (left side manifold) and right bank (after the catalytic converter).

Well there are four--left side cross over pipe, right side cross over pipe, before catalytic converter and after catalytic converter.

Went to autozone and had them read the codes to me, I remember some stuff about left bank, bla, bla, bla, and I thing right bank too, bla, bla, bla. The scanner also called the Mass air flow sensor.

What are the possibilities of testing all the O2 sensors, and if any two are good, place them in the left bank and after the catalytic converter (right bank) and just calling life good? Or, does the "system" use all four of those O2 sensors?


I replaced the O2 on the right side of the Y-pipe; the heater circuit was open. Still had codes, so I replaced the MAF. All codes gone except a transmission code. That "Service Engine Soon" light is sooooo annoying. I'm gonna get rid of it sooner or later.