Replacing Oem O2 Sensors With Generics

[mts]

Originally posted by "mazda-fla"

 

I just got done replacing my O2 sensors on Bank 1, (right side of engine, nearest firewall). The process would be similar for Bank 2, (left side of engine, nearest radiator).

 

Step One: Get a 6 point 22-mm (7/8 inch) O2 sensor wrench. It can either be the "socket" type, or the "claw" type. Either type will work. You can either buy it, or get a loaner set for free from Autozone:

 

 

Step Two: Warm up engine. The O2 sensor is easier to change on a warm engine.

 

Step Three: Unplug the 4-wire connector for the Right Rear O2 sensor.

 

 

Step Four: Unplug the 3-wire connector for the Right Front O2 sensor.

 

 

Step Five: For the Right Rear (after the pre-cat) O2 sensor, jack the car up (on the driver's side) a little bit more than you would if you were changing the oil or changing a tire. Then slide a jackstand under there for safety. Crawl under the car (from the front). The Right Rear O2 sensor is near the place were you would remove the oil plug doing an oil change. It is after the pre-cat, on the side of the engine nearest the firewall. Reach up in there with the O2 sensor wrench tool and remove the O2 sensor.

 

Step Six: Put on a long sleeve shirt and two surgeons gloves on your left hand (or pair of mechanics gloves) to do the Right Front, because you will definately wind up touching something hot on this one. Use the O2 sensor tool, with 12 to 18 inches of extension, and the longest breaker bar you have. You have to feel around for the Right Front O2 sensor (located in the exhaust manifold, before the pre-cat). You can't see it from the top of the car, unless you lower a small mirror in there. I found it easier to remove this from the top of the engine, rather than trying to do it from the underside of the car. Put the wrench down, holding it with your right hand, and guiding the socket tool with your left hand. Using feel to put it on the O2 sensor. Make sure you have the sensor tool properly fitted to the O2 sensor, or you may strip the O2 sensor. Then remove the sensor. The front one may be frozen on, but with a large ratchet you should be able to remove it.

 

 

Step Seven: Now is when you start saving some money, using a generic O2 sensor from www.oxygensensors.com and splicing them onto your existing connectors. The front O2 sensors are generic 3-wire sensors, and the rear O2 sensors are generic 4-wire sensors. The generic 3-wires are $44.95 each and the generic 4-wires are $51.90 each. Shipping is free for orders over $50.00. They ship the same day that you order them, and arrive at your house via USPS Priority Mail in about 3 days. The old OEM one is on the right, and the new generic one is on the left.

 

 

Step Eight: Using a pair of sissors, carefully cut a slit a few inches up the heat insulator that wraps the wires.

 

 

 

Step Nine: Cut the wire, slide a heat shrink tube over the wire, then crimp the connector.

 

 

Step Ten: Slide the heat shrink tube over the crimped connector. Then, using a lighter, match, or heat gun, heat the heat shrink tube until the connection is completely sealed.

 

 

Step Eleven: Stagger Cut each wire approximately 1/2 inch. And repeat the procedure for all wires. The 3-wire O2 sensors will have a signal to computer wire, and two heater wires. The 4-wire O2 sensors will have that, plus fourth wire for the ground. Color coded diagrams for your particular application are provided with the O2 sensor, so you can match the wire colors up.

 

 

Step Twelve: Now re-wrap the heat insulator that wraps the wires over the wires again. I like to then wind some black electrical tape around the entire splicing area.

 

 

Step Thirteen: This is the final completed assembly, with new generic O2 sensor spliced onto old connector.

 

 

Step Fourteen: Apply some anti-seize compound, included with the new sensor, on the threads of the new O2 sensor. Be careful to only apply it to the threads, do not get any on the sensor probe itself. Also be careful not to drop or bang the new sensor, because you may damage the fragile ceramic cell inside the sensor.

 

 

Step Fifteen: Reinstall the O2 sensor, then plug in the connector.

 

Step Sixteen: If you changed the O2 sensor because of a CEL. Then you will either have to clear the code with an OBDii reader, or unplug the negative therminal on the battery to clear the code, or drive the car for a few days and have the CEL turn off by itself.