Catalytic converter after i cut out the catalytic converter and unclogged the exhaust manifold converter the exhaust manifold where the upstream o2 sensor goes still glowing red and i changed everything in the hood car only revs 3RPM NO POWER WILL HAVE TO KEEP MY FOOT ON THE PEDAL TO MOVE IT I WAS TOLD TO GET A NEW EXHAUST MANIFOLD

O2 sensors are located in the exhaust system, before and after the catalytic converter, (Cat).
Sensor 1, (Upstream sensor), is before the catalytic converter, often positioned in the exhaust manifold or in the down pipe attached to the manifold.
Sensor 2, (Downstream sensor), is positioned under the vehicle after the catalytic converter. They usually stick out at 90 degrees to the exhaust and can be a real pain in the tailbone to get out.

On most vehicles, the sensors are screwed in to the exhaust pipes or exhaust manifolds, usually under the car/truck , in the vicinity of "under the front seat" area. They are usually the size of your thumb, and have a wire going to them.

it has both. upstream is the first sensor you come to when you follow the exhaust from the manifold to the rear of the system. the down stream is the next one you come to.

4 total. 1 each manifold. Then 1 before, 1 after the CAT. You should be able to count and trace them from the connections on the top of your engine. Good luck

One would need the year, make, model, and engine size to tell you exactly where they are and how many.

O2 sensors are always in the exhaust stream, either in the exhaust manifold that is attached to the engine, or in the exhaust piping after the exhaust manifold. Some models have one for each bank of the engine, and some have only one sensor to monitor oxygen content. These engine sensors that the computer uses to "fix" or adjust the air/fuel ratio are called the upstream oxygen sensors. If the car is equipped (as most are today) with an oxygen sensor after the catalytic converter, this is called a downstream oxygen sensor. They are the same and do the same thing, but the downstream sensor is only used to monitor the efficiency of the converter. The upstream sensor(s) are what the computer reads to adjust or "trim" the fuel delivery.

So some older cars have only one o2 sensor. Not far from the engine in the exhaust stream. Some newer cars with dual exhaust (2 converters) may have four o2 sensors. 1 for each bank of the engine and 1 behind each catalytic converter. A 2005 Buick Century with a 3.1L engine, for instance, has only two o2 sensors: one (upstream) in the exhaust down pipe, and one (downstream) just behind the catalytic converter.

There really is no diagram.. The upstream O2 is in the exhaust manifold or pipe before the catalytic converter and the downstream O2 (if equipped) is after the catalytic converter in the Catalytic converter itself or the pipe just after the Catalytic converter.

One of the easiest ways to locate the upstream sensor is to follow the exhaust line from the engine towards the catalytic converter. In most vehicles, the upstream sensor is close to the exhaust manifold compared to the catalytic converter.

The O2 sensors are located in the exhaust pipe just off the engine exhaust manifolds and before the Catalytic Converter. A V6 has 2 of them, one for each bank of cylinders, they are referred to as the "Bank 1 and Bank 2 Upstream sensors". There is also a sensor that looks like a O2 sensor it is located behind the Catalytic Converter, its job is to monitor the efficiency of the Catalytic Converter and signal you with a check engine light and a code P0420 if the Cat is not doing its job. Each sensor has its own set of fault codes if problems are sensed in the O2 levels in the exhaust (fuel control problems) and other problems like the heater circuit in the sensor is defective.

since that is a Boxer engine it will have one O2 sensor at the base of each exhaust manifold. and since it is newer than a 1996 it will have one or two more O2 sensors behind each catalytic converter so you will have three or four ( O2 sensors) fuel air ratio sensors you need to check if you are having a problem. the two at each exhaust manifold are the upstream and the ones at the catalytic converters are the downstream. hopefully that engine only has one catalytic converter going into one exhaust pipe. the exaust manifolds are under the engines cylinder heads (under the engine).

One of three (3) possibitlies:
1. Catalytic Converter is malfunctioning.
2. O2 Sensor is malfunctioning. This will be the O2 Sensor located on the Catalytic Converter. However you should check and/or replace both sensors if needed.
3. You have an Exhaust Leak.
In Order of checking:
A. Check and Repair any Exhaust Leak.
B. Replace the O2 Sensor on the Catalytic Converter 1st. Also Known as the Downstream O2 Sensor or HO2 Sensor.
C. Replace the O2 on the Exhaust Manifold prior to the Catalytic Converter. Also Known as the Upstream O2 Sensor.
D. Replace the Catalytic Converter.
Let me know if this helped, or if you have any additional information, problems or questions. Feel free to contact me at FixYa.com!