o2 sensor buick regal 1999?

Question

placement of o2 sensor on 1999 buick regal

Answer 1

I do not own a repair shop, but can answer your question. The previous post by eferrel captures the correct generic information for O2 sensors.

The 1999 Buick Regal comes in two trim levels: LS and GS. There are many more LS so my response is for this model. The GS is a supercharged version which is not as common.

The 3.8L engine has one pre-catalytic and one post-catalytic converter O2 sensor. The 'pre' is located dead center at the back of the engine where the exhaust manifold pipes join, nearly flush with the fire wall. It measures emissions for both engine banks (3+3 cylinders).

The 'post' is immediately downstream of the catalytic converter.

Both of these are tough to access and as eferrel says, a special slotted socket should be used for removal and installation. Rounding off the flats or breaking the O2 is pure misery.

Also, most O2 sensors come with a small packet of anti-seize lubricant. It is necessary to apply this to the O2 threads so that the sensor does not become 'welded' in place due to very high exhaust temperatures. It is very important to not get any of the anti-seize on the sensor nipple, as it will ruin the sensitive internal measuring device when it burns off.

However, the question behind the question is 'why do you want to replace this sensor?'

An O2 sensor can set a code for lean or rich running, and it is correctly performing its function. Often times there is a secondary failure that causes the O2 to actuate. Fuel control is the main reason for O2 setting a code. To test the O2 sensor, a diagnostic computer is required to measure the voltage swing (typically between 0.2 and 0.8 V) and switching speed. A 'lazy' sensor will not switch at the required frequency and set a code.

Best to pay a diagnostic shop to read the codes and determine root cause. Replacing parts is a very expensive way to repair a car! Don't know if this is your situation, but this is a fairly common scenario.
Good luck,
Marc

Answer 2

The O2 sensor is located in the exhaust system, sometimes in the exhaust manifold (4 cyl) others in the pipe. It may be located at the inlet or outlet of the catalytic converter. You can identify it as it is screwed into the fitting and has 2 wires plugged into it.
Get the replacement, and if you can't get to it with an open or boxed end wrench, you will have to buy a special socket that has a slot in the side to accommodate the wires.

Answer 3

There are at least two oxygen sensors in this car, possibly three. I am not sure what type of motor you have in this car so it is not possible to say for sure where. There will be one in the pipe that exits the convertor on any of these cars. The other one or two depending on motor type will be screwed into the exhaust manifold(s) or the pipes leading down into the convertor inlet. Hope that helps.

Answer 4

i own a repair shop,and you didn't finish the question if you replacing it,or what i cant help on this one sorry,,good luck with it.happy new years.