The scan tool is the device that can reveal the problems that occur on one of the oxygen sensors in your vehicle. You will need to use one if you want to troubleshoot the problems related to your oxygen sensors. The scan tool will show trouble codes as the indications for the fault, and it will also tell you which sensor is having a problem by pointing the sensor positions.
There are three locations for the oxygen sensors, which are sensor 1, sensor 2, and sensor 3. Meanwhile, the scan tool will also indicate the problem either from cylinder bank 1 or 2.
This is important because engines on late-model vehicles are equipped with multiple oxygen sensors. Using the scan tool will make it easier to point out which sensor on which cylinder bank needs to be fixed.
If your vehicle is equipped with a straight 4 or 6-cylinder engine, then all of the oxygen sensors will be located in the only cylinder bank. You can usually locate the oxygen sensor or air/fuel sensor #1 in the exhaust manifold. Meanwhile, oxygen sensor #2 is typically located behind the catalytic converter.
If the vehicle features V6 or V8 engines, sensor #1 is always located on the same side as cylinder bank 1. Refer to the vehicle’s firing order for this case.
On engines with V6 or V8 design produced by Ford, the cylinder bank #1 is usually on the right front side of the vehicle, especially for cars and trucks with rear-wheel drive mechanisms.
Meanwhile, cylinder bank 1 is located on the back right side of the vehicle’s engine for cars or minivans built with transverse V6-mounted engines. This applied to cars and minivans produced by Ford.
If your vehicle uses either a V6 or V8 engine from GM or Chrysler, the cylinder bank 1 is usually located on the left front side (driver’s side) for cars or trucks with rear-wheel drive.
The cylinder bank 1 is typically located on the right front side (passenger’s side) on cars or minivans with transverse-mounted engines. This applies mostly to cars manufactured by GM.
For Chrysler cars with front-wheel drive mechanisms, including cars or minivans, which are built with transverse-mounted engines, the cylinder bank 1 is located on the backside of the engine, which is near the firewall. You can notice the location on the right side of the engine.
The location of cylinder bank 1 will also depend on the model and type of the vehicle. Make sure that you refer to the owner’s manual to get more information.
But you can find the exact location of cylinder bank 1 by looking at the ignition system of your vehicle. If the vehicle is equipped with an ignition system with no distributor or ignition with coil-on-plug design, there might be marks or lettering on the plug wires to pinpoint the location of the cylinder bank 1.
In a case where the V6, V8, or V10 engines are built with dual exhausts and dual converters, you will be able to see the label for Bank 1, Sensor 2 and Bank 2, Sensor 2 on the downstream oxygen sensors. You can also notice the label for Bank 1 Sensor 3 on the downstream oxygen sensors if the exhaust manifold has both upstream oxygen sensors.
Prior to the process of replacing problematic oxygen sensors, you might need to identify which sensors are causing the fault codes.
Replacing oxygen sensors could cost you a lot of money, so make sure that you know the exact location of the faulty sensors before you start the process to replace them.