An oscilloscope is the best method for testing. Faulty heaters do not allow the sensors to reach operating temperature fast enough and the vehicle may remain in open loop for longer periods of time. With relatively richer mixtures present around the downstream oxygen sensor, voltage inputs to the computer will be above the 450mV bias voltage. Combustible gases will burn in the presence of oxygen only on the detector, causing a rise in temperature and a corresponding rise in electrical resistance. Replacing the oxygen O2 sensors may sometimes fix the code, but in most cases the catalytic converter needs to be replaced to fix the problem. If that is your case, assure good electrical connection and clear the code.
On the V6 24V the driver's side of the engine contains Cylinder 1, so the configuration is shown here: Nov 28, 2010 -I don't have a location of the Bank 2 sensor, so you'll have to guess on it by determining how many sensors you have by inspecting the exhaust system from the exhaust manifold down to the catalytic converter and past the catalytic converter which is downstream. What repairs can fix the P0428 code? While downstream oxygen sensors are constructed the same as upstream oxygen sensors, the values that they generate are different. If the P0425 code is combined with other codes, try fixing the other codes first. Improper rich indications will cause lean operating conditions that may result in loss of power, hesitation, surging, poor idle quality and possibly converter damage. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
Catalyst sensors are often used to detect hydrocarbons but rely on the presence of oxygen to function. Oxygen sensor failure should be verified before replacement. Anything before the catalytic converter is upstream. What causes the P0428 code? Additional fuel can cause the catalyst temperatures to rise due to an afterburner effect in the converter. Do not pack or store the sensor with silica gels. We are not responsible for any actions you take on your vehicle. When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.
Sometimes techs report that oxygen sensors are often replaced blindly in order to avoid costly catalytic converter. If all system wiring, connectors, and components Including fuses appear to be in normal working order, connect the scanner or code reader to the diagnostic connector and record all stored codes and freeze frame data. Therefore, a test is regularly run that monitors how many high resolution pulses are not detected. Nowadays vehicle with emissions control systems use heated oxygen sensors. A faulty oxygen sensor due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit can cause the following symptoms. If the correct temperature is not detected, then the code will be stored and the service engine light may be illuminated.
When combustible gases raise the temperature of the detector and a rise in its resistance, it causes an imbalance in the circuit and produces an output voltage signal. Oxygen sensor failure should be verified before replacement. The computer will respond by commanding additional fuel. Symptoms Symptoms may be as minor as only a stored code and an illuminated service engine soon lamp or as major as a no start or engine stall condition. The symptoms that accompany a P0428 code can be nothing more than a simple Check Engine light coming on. This method is 100% effective to check if the electrical harness involving the Catalyst Temperature Sensor, but it can be tricky to obtain the schematics.
As the catalyst efficiency degrades, its ability to store oxygen is reduced and the catalyst output becomes more variable. This also produces high oxygen levels in the exhaust. Every cam pulse should entail 64 high-resolution pulses. Malfunctioning heaters also allow the sensors to cool down during periods of extended idle. What are the symptoms of code P0425? The currently selected is for the Mercedes-Benz makes. When the output voltage from the sensor drops below bias voltage levels, the computer will command a rich mixture again.
Bad oxygen sensors are also a possibility but if this is the case an oxygen sensor code will usually accompany the direct ozone reduction catalyst temperature code. Common mistakes when diagnosing the P0428 code By far, the most common mistake a technician makes is simply replacing the catalytic converter and not thoroughly researching what happened to cause the problem. The two methods involve testing the oxygen sensor using and oscilloscope or a multi-meter. Technicians report that repeated direct ozone reduction catalyst failure occurs when other codes are present and left unattended for long periods of time. The oxygen sensor will sense only the increased oxygen content and input to the computer will be below bias voltage levels.
Do you have a code that describes which O2 sensor is not responding correctly? This provides adequate oxygen for storage while maintaining cool enough operating temperatures to prevent catalyst damage. Enter the 5 character trouble codes in the search box and submit the search. How do you troubleshoot code P0425? Several tools may be needed to successfully diagnose this code if no exhaust leaks are detected. The oxygen sensor provides the computer with necessary information to maintain favorable operating conditions for the catalytic converter. The list of automotive Makes at the right edge of the screen.
In addition to controlling the converters operating conditions for emissions control, the computer uses the oxygen sensors to tailor fuel trim providing a balance between fuel economy and performance. When the exhaust sample is rich, there is less oxygen content in the exhaust as compared to the atmosphere. Proceed by raising the vehicle and pointing the temperature gun at the exhaust pipe before and after the catalytic converter in question this is much easier if the temp gun is equipped with a laser pointer. This will result in an Open Loop operation. There are approximately 64 high resolution pulses for every cam pulse. Engine misfires are known to deteriorate the platinum element of the converter, as is excessively rich exhaust. The next most common misdiagnosis comes from oxygen sensor replacement.
Common Misdiagnosis The most common misdiagnosis is caused by not thoroughly investigating what led to direct ozone reduction catalyst failure. Catalytic converter failure occurs when other codes are present and left unattended for long periods of time. Need help with a P0428 code? The list of automotive Makes at the right edge of the screen. The temperature sensor has an attachment for attaching the temperature sensor to the attachment point of the catalytic motor vehicle radiator, and includes an electrical identification unit for identifying the catalytic motor vehicle radiator. Remember to diagnose and repair oxygen sensor codes, fuel trim codes, fuel mixture codes, or misfire codes first before attempting to diagnose a catalytic converter code. On the other hand, it could be something far more serious like the engine stalling or even refusing to start in the first place. This just leads to added expense.