Oxygen Sensor..How many are there?

How many total oxygen sensors are there in my 1996 GMC Jimmy?

I understand the concept of "Bank 1, Sensor 1", etc. But, according to all the other posts Ive been reading, the bank one sensor one is the one on the Drivers side, closest to the engine, but Ive looked under there and it looks like the Bank 2, sensor 1 is the closest to the engine, passenger side. The last one is way out after the catalitic converter.

The code i get, P0133, States theres an issue with the sensor Bank 1, Sensor one.

Please help!!!

Bank 1 = cylinder 1 side, the down stream H02 sensor is used for checking the catalyst on your converter.If the Cat is blown, it will throw a code P0420 (bank 1), or P0430 (bank 2).

On 1996 there are 4 O2 sensors. Bank 1 sensor 1 is next to the exhaust manifold on the driver side. P0133 means the PCM detected a slow response from bank 1 sensor 1. Could be a poor connection anywhere from the sensor to the PCM, sensor ground circuit, or the oxygen sensor itself needs replacement.

Thanks for all the advice. So far, I've seen only three sensors. All three vieable from the bottom of truck. One is on the driver's side, which I would assume is Bank 1, Sensor 2. The other one on the passenger side, Bank 2 sensor 1, and the third one past the converter, bank 1, sensor 3?

Its that first one (bank 1, sensor 1) Im having trouble locating. By the way, my truck is Vorctec.

thanks.

Visual inspect all H02 sensor wires for heat damage, there should be no bare wires, that could short a signal out.

There are 3 sensors in the "Y" pipe and one sensor after the converter.

Bank 1 sensor 1 is next to the exhaust manifold on the driver side.
Bank 2 sensor 1 is next to the exhaust manifold on the passenger side.
Bank 1 sensor 2 in just in front of the converter inlet.
Bank 1 sensor 3 is at the outlet of the converter.

Thanks so much...Got it! That "Y" visual helped me get a better look at it. Thanks to both of you for the help.

Are all sensors the same part number? I noticed that Bosch makes good O2 sensors, but does the same sensor fit in all four locations?

the last one I installed was a Bosch, lasted over 125,000 miles. Part #15703. Can I use this same one for all four other locations?

Is the a better brand other than AC Delco and Bosch that you can reccomend?

THANKS

The sensor itself is the same. You'll need to visually check the length of the harness and the connectors. Some use longer or shorter harness's, and some flip the connector ie, male or female on the sensor harness.