What are Oxygen Sensors
also known as O2 Sensors

What is an Oxygen Sensors?
Also Known as        : O2 Sensor, Ox sensor, Oxygen sensor
Purpose                   :  Measures Oxygen content in exhaust stream.

In today’s modern engines the fuel delivery system has changed dramatically since the early days of carburetors.  On a carburated  engine the amount fuel that is delivered to the combustion chamber was controlled by a jet size and the  throttle plate size and position. Although, this method is fairly simple, it is not very precise and often delivered too much fuel causing a rich condition or too little fuel causing a lean condition to the engine.

Fuel injected engines control the  amount of fuel delivered for combustion precisely by increasing or decreasing the time a fuel injector is active. This time is controlled by the engine computer ECM and the sensors that send information to it. One of the key sensors is the O2 or Oxygen sensor which is made of a bi-metal ceramic element that reacts to the amount of oxygen, or lack of it, in the exhaust system.

An O2 sensor indicating a lean condition would show that there was excess oxygen remaining in the exhaust after the burn and signal the computer that more fuel was needed to maximizes the remaining air available during combustion.

An O2 sensor rich condition indicates that all the oxygen was used during the burn cycle and that unburned fuel was found in the exhaust because of a lack of oxygen.  Unburned fuel i.e. hydrocarbons are a strong pollutant and a wasteful use of expensive gasoline.

The engine computer (ECM) monitors these oxygen sensors and controls the fuel delivery via the fuel injectors.  If there is too much fuel remaining in the exhaust system the computer will shorten the length of time the injectors are on.  When there is too little fuel remaining in the exhaust system the ECM will increase the time the injectors are on allowing more fuel.

There are often multiple O2 sensors on a engine so that the computer can measure remaining fuel thought out the exhaust. the hot exhaust will continue to burn remaining fuel provided oxygen is present.  a few common locations for O2 sensors are in the exhaust manifold  know as up stream because they are before the catalytic converter and  down stream after the catalytic converter in the exhaust pipe.

www.oehq.com is your best source for Original equipment O2 sensors

 

Could this be a motor mount problem?

My 2002 325i has 55K pristine miles on it and drives and rides very smoothly, except in one instance. When stopped at a light, for example, with foot on the brake and car in D, I notice a vibration. Keeping the brake on and shifting to N, the tack dropgoes up very slightly and the vibration diminishes greatly. Told my BMW indy about it and he said that he didn’t think it was an idling/timing problem, but rather failing motor mounts. What do you guys think? If it is, he’ll allow me to supply the mounts. I’m just a regular driver ans would like mounts equivalent to the BMW ones, but don’t want to pay BMW a pound of flesh; so, where would you recommend that I get good mounts? Thanks.

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The Bugatti Veyron EB 16.4 is a rear mid-engined supercar. It is the most expensive modern car in the world at $1,600,000. The Super Sport version is the fastest road-legal car in the world, with a top speed of 431.07 km/h (267.85 mph).[4] The original version has a top speed of 408.00 km/h (253.52 mph).[5]

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