How do I check An Engine Oxygen Sensor?

All engines run on an optimum fuel to air mixture called "stokiometric" which means chemically balanced. This balanced fuel to air ratio is 14.7 to 1, 14.7 parts air to 1 part fuel. The oxygen sensor is created using the active chemical such as zirconium, electrochemical (also known as Galvanic), infrared, ultrasonic and very recently laser. When a lean mixture code is detected by you or a technician the first tendency is to replace the oxygen sensor. The best way to check the operation of the sensor is to run a simple test. No matter if your engines
oxygen sensor has one wire or four there is only one sensing wire that feedbacks information to the PCM. To find this wire you will need a car repair manual. If a trouble code is present that pertains to an oxygen heater sensor failure, replace the sensor to repair the problem. An oxygen sensor must be warm before it will operate properly.

Warning: If a malfunction exists with related components such as an engine misfire or engine vacuum leak do not perform this test. The oxygen sensor is designed to operate within a particular range, if this range is exceeded the sensor will give the appearance that it has failed.

GM Oxygen Sensor - (appearances will vary)

Oxygen Sensor Test
Tools needed to perform these tests: Voltmeter

* Step 1 - Once the oxygen sensor sensing wire has been located connect a volt meter to the feedback wire and ground. Select the millivolt operation on the meter.

* Step 2 - Next, start and run the engine at idle until warm (about 15 minutes). Observe the voltmeter; it should bounce slightly at whatever voltage the sensor is centered at (about 150 millivolts).

* Step 3 - Continue to observe the meter and have a helper rap the throttle. The meter should drop for a split second as the mixture leans out in the first milliseconds of the throttle bore being opened. Then quickly rise for a spit second as the throttle closes and the mixture richens. The volt meter should stabilize at the original operating voltage when the engine returns to idle.

Performance Exhaust System

A performance exhaust system can be anything from a simple “cat-back” system to give you a little better sound to a full tuned set of headers to replace the restrictive exhaust manifolds. Always consult state and federal emissions laws before modifying your vehicles exhaust system.
Performance Exhaust

There have been numerous advances in the technology for performance exhaust systems. While standard exhaust systems are designed as cost efficient as possible, a performance system is usually made from a higher grade of material with a more performance-oriented design. The exact type of performance exhaust often varies depending upon the vehicle and application. Adding performance exhaust systems is easily handled with just a few tools and will boost performance immediately.

Inspect your exhaust system on occasion to ensure that there are no cracks, holes or rust. Only inspect the exhaust system after the engine has cooled down to avoid burns. When exhaust replacement is required a performance exhaust system might be a good consideration. After a new exhaust system has been installed it is normal for funny smells to be produced. This condition will stop once the exhaust system has been heated and cooled a few times. The reason for the smell is a new system is manufactured using oils and paint and until the impurities are burned off it will create an odor.

Rebuilt or Refurbished?

What is the difference?
A rebuilt: replacement part, engine, transmission or differential means the unit has been disassembled and the "wear" items have been replaced such as bearings, brushes or guides etc. A rebuilt part will sometimes have individually painted parts. A refurbished unit is basically cleaned, painted and then resold. Obviously you are better off with the rebuilt unit than refurbished, some repair facilities will try to pass the refurbished unit off as a rebuilt unit so be sure you are getting what you ask for. If you are unsure of the integrity of the repair shop ask to see the part or unit before it is installed. Most dealerships and high end repair shops will only install new parts. New parts are optimum for best performance and longevity, rebuilt is the next best thing. You should only agree to a refurbished replacement part as a last resort.