Mercedes-benz w203 oxygen sensor replacement – (2003-2005) c320 pelican parts diy maintenance article electricity bill bihar electricity board

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The oxygen sensors (also called O2 sensors) are one of the most important elements of the modern fuel injection systems. A finely tuned fuel injection system with an oxygen sensor can maintain an air/fuel ratio within a close tolerance of .02 percent. Keeping the engine at the stoichiometric ratio (14.7:1 air/fuel ratio) helps the engine generate the most power with the least amount of emissions.

The oxygen sensors are located in the exhaust system of the engine, and they sense the oxygen content of the exhaust gases. There are two on the Mercedes C320: one on each side of the catalytic converter. The sensor located just in front of the catalytic converter measures the mixture of the exhaust gas exiting the engine. The sensor located after the catalytic converter is used to measure the performance of the converter by comparing the O2 levels before and after. The amount of oxygen in the exhaust varies according to the air/fuel ratio of the fuel injection system. The oxygen sensor produces a small voltage signal that is interpreted by the electronic control unit (ECU) of the fuel injection system. The ECU makes constant adjustments in fuel delivery according to the signal generated by the oxygen sensor in order to maintain the optimum air/fuel ratio.

There are a few signs that your oxygen sensor may be failing. In general, it is difficult to diagnose problems with the sensor, unless all of the other components in the fuel injection system have been checked and determined to be operating correctly. Some of the symptoms of a failed oxygen sensor system are: Irregular idle during warm-up, irregular idle with warm engine, engine will not accelerate and backfires, poor engine performance, fuel consumption is high, driving performance is weak, CO concentration at idle is too high or too low, check Engine Lamp is illuminated.

In general, if the oxygen sensor is not working, the car will be running very poorly, and will also be outputting a lot of harmful emissions. The cars computer will usually give a warning signal that lights up the Check Engine Lamp if the signal received by the computer is out of its normal range. Sometimes the computer may output an error code stating that the oxygen sensor is reading out of range, when in reality the values registered by the O2 sensor are accurate because there is something else wrong with the fuel injection system. Prior to replacing the oxygen sensors, make sure there are no other codes being recorded that may affect the O2 sensor readings.

Troubleshooting the complete fuel injection system is beyond this project’s scope. If you think that the oxygen sensors may be causing some of your fuel injection problems, they should be replaced. In general, I recommend that you do this as needed. You will have to jack up the car and secure it safely on jackstands to gain access to the sensors.

Begin by removing the under trays on the front of the car. There are two trays, the first is the engine tray and it is held in place by six 8mm screws, next is the transmission tray. It is also held in place by six 8mm screws but two of them are shared with the engine tray.

On the front oxygen sensors, you’ll need to get a little creative. The front sensors are mounted in a really tight space and at an odd angle. To loosen it, you’ll need patience and to use a special type of 22mm crow’s-foot wrench with a slit cut in the side. When you remove the O2 sensor, you will probably find that it is coated with black soot. This is normal for an old, worn out O2 sensor and usually indicates a rich running condition.

Install your new sensor snug-tight, and torque to spec. It’s also a smart idea to add some anti-seize compound to the threads of the plug before you install it, but make sure the anti-seize doesn’t get into any of the slits on the head of the sensor. Check the sensor first though, as new ones usually come with a dab of anti-seize already on the threads.

Always purchase the correct sensor for the car. The wire resistance and proper connection to the harness are vital for the performance of the sensor. Snipping and soldering wires together can affect the resistance in the wire and cause the sensor to give false readings. While the factory sensors are expensive, in the long run you will probably not end up saving yourself any money and end up doing the same job twice if you install cheap generic sensors.

Comments: I have change do o2 sensor bank 1 n i reset after that but the warning engine come out after 5 hour the car use. Then i cek use obd the code p0133 and p0134. I didnt now what is the problem after i change a new o2 sensor for mercedes c180

Comments: i recently got a code for P0161 . ordered and replaced bank 2, sensor 2 with bosch O2 sensor. i replaced today, cleared CEL using BAFX bluetooth OBDII scanner, and when i start the car, CEL if off, but if i shut off and restart the car, it comes back on. i had to reset it a couple of times to turn CEL off. Took the car for a drive, and CEL remains off. i check again for faults, and P0161 is now a Pending Fault. CEL hasn’t came back on, but i am afraid if i do a cold start in the am, CEL will come back. 02 C32 AMG

Comments: I have a problem with the car, the columns move slightly when the vehicle is standing and not driving, and while driving they even jump about 100-200 columns, I checked with OBD2 and P2a00 records. Can this help? i have mercedes benz c220 w203 2008

Comments: I RECENTLY REPLACED ALL 4 SENSORS AND SHORTLY AFTERWARDS I HAD THE CEL LIGHT UP. I USED MY SCANNER AND GOT THE FOLLOWING CODES 130,135,136,141,150,155,156, & 151. ALL CODES ARE P0*** FORMAT. I CLEAR CODES AND AFTER SHUTTING OFF THE CAR AND RESTARTING THE CODES WILL ALL COME BACK WITHIN 10 MINUTES WHETHER IM DRIVING OR NOT. I HAVE RECENTLY CHANGED ALL PLUGS, WIRES, COILS, VACCUUM LINES, CAM POSITION SENSOR, CRANK POSITION SENSOR, NEW AIR FILTERS, ENGINE AND TRANSMISSION MOUNTS, ENGINE GROUND STRAP. OTHERS HAVE SAID THIS IS ACTUALLY CAUSED BY A FAULTY MAF SENSOR ANY THOUGHTS?

I have a 2002 C320 with 149,000 miles. Shortly after purchasing last year Engine light on and showing codes P0432 and P0422 bad 1st Cats, both sides. I have changed the Plugs a few months ago, nothing else. The cats do not smell and do not rattle. Is there any chance the O2 Sensors are causing this? Both Cats bad seems strange, I have been driving MB for like 10+ yrs and never replaced cats.