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Cadillac Oxygen Sensor Troubleshooting

Can bad oxygen sensors cause a Cadillac to run rich? What are some of the codes related to the Cadillac oxygen sensors? The oxygen sensor is a pollution control device that monitors the level of oxygen in the exhaust and communicates this information to the car’s computer in order to regulate the air/fuel mixture entering the engine. Typically, problems trigger error codes which need to be further diagnosed with the help of scan tools. Moreover, it is possible to troubleshoot other problems and obtain remedial steps through the help of valuable and verified Experts online.

Read below where Experts have answered a few questions for other Cadillac owners.

Are oxygen sensors responsible for a 1993 Cadillac Deville to experience high CO levels and how can it be reduced?

Typically, high CO levels is a result of the car running too rich and the oxygen sensor is the device on the engine that determines the fuel mixture. This engine has two of these sensors and it could be a problem with just one of them. However, to troubleshoot and diagnose the problematic sensor can be challenging. Since finding a reliable repairman for older Cadillacs, it is recommended to replace both oxygen sensors. Also, ensure the engine is operating at 220 degree Fahrenheit. This temperature is optimum for fuel economy and if it runs cooler than this, it will run rich.

How to pass inspection with an oxygen sensor wire that is damaged and the check engine light illuminated on a 1997 Cadillac SRX?

Normally, State inspections are carried out using a computer which communicates with the on-board computer through the OBD-II diagnostic port. There may not be a way to get around this machine, ‘clear’ the resultant codes and pass the inspection. Once the codes are cleared, the on-board computer's ‘Readiness Monitors’ change to ‘Not Ready’ which is one of the aspects the inspection machine is meant to detect. If more than one monitor is ‘Not Ready,’ the car has failed the inspection. Next, the vehicle needs to be driven and is called a ‘Drive Cycle.’ During this time, the on-board computer resets and re-checks all the monitored systems. If it detects that the problem still persists, the engine light will return. Therefore, the oxygen sensor has to be repaired for the Cadillac to pass the inspection.

Is the code P0420 related to the oxygen sensor on a 2004 Cadillac CTS?

The P0420 code is fairly straightforward and common. It indicates a failing catalytic converter. The oxygen sensors are responsible to measure the amount of emissions going into the exhaust and then out of the converter. If the catalytic converter is not efficiently cleaning the exhaust enough to meet the specifications, the converter goes ‘below threshold’ and the P0420 gets set though oxygen sensors are working correctly. To rectify this issue, ensure there aren’t any current cylinder misfires or leaks in the exhaust system, such as the manifold. If these are fine, most likely the catalytic converter is becoming faulty and needs to be replaced. While replacing this component, the electrical connector of the oxygen sensor which is attached to the exhaust manifold needs to be disconnected and re-connected or replaced (as necessary) to the new converter.

Why are oxygen sensor related codes (P0100 and P0110) set and how can they be erased on a 2000 Cadillac Catera?

To begin with, oxygen sensor codes are typically an aftermath or after effect of a related problem and not always an indication of a problem with the O2 sensors. This implies that the codes are getting set because some problem is making the car run either rich or lean. The job of the O2 sensors is to detect these anomalies. When the O2 sensors read exhaust from faulty components, they try to compensate for the problem. To clear the codes, first the system needs to be scanned to pinpoint where the problem exists in order to diagnose and repair the actual component at fault.

Why has the O2 sensor stopped working on a Cadillac Deville if the exhaust sensor harness plug melted?

The Cadillac oxygen sensor has probably shorted out when the wires got damaged. Therefore, it would be wise to replace the sensor to avoid the risk of a shorted O2 sensor, damaging the PCM. The new oxygen sensor normally comes equipped with a harness. Once installed, you need to reset it to maintain the memory and address any idling issue.

What is the location of the O2 sensor bank 1 sensor 2 on a 1996 Cadillac Seville SLS?

The oxygen sensor bank1/sensor2 can be found under the vehicle, mounted to the exhaust pipe just before the catalytic converter.

As seen above, oxygen sensor problems can directly affect the functioning of the car or throw back codes which need to be scanned and diagnosed further. On some occasions, problems with the Cadillac oxygen sensor is closely connected to other exhaust components present in the vehicle. The above information covers some of the problems that can arise with oxygen sensors. If you are facing a different issue, troubleshooting tips and repair options are available through insights from Experts. Verified Expert answers are provided at your convenience, from the comfort of your home. 

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