Oxygen Sensors

usually if catalictic converter is bad , it will stink like rotten eggs when u drive if you can get under car and shake converter, if it is bad it will rattle. other than that there is no good way to test a catalictic converter

This is the exact opposite of the truth. The rotten egg smell means that the catalytic converter is working properly.

"It's (the smell) hydrogen sulfide or H2S. It does not exist in the fuel or oil, which is why you can't smell it at the gas station. It does, however, come from the gasoline. Almost all gasoline contains organic sulfur compounds with sulfur levels ranging from 30 to 100 parts per million, approximately. "As the fuel burns, the organic sulfur compounds break down into simpler compounds. If the engine is running lean (more air than is needed to burn the fuel), the sulfur is likely to be SO2, or sulfur dioxide. The catalytic converter can change this into SO3 (sulfur trioxide), which then reacts with the catalyst to form sulfates on the catalyst. Over several minutes there is a build up of sulfates. If the engine suddenly starts to run rich (not enough air to burn all the fuel), such as when you stop at a red light, climb a steep hill, or brake hard to slow down, the chemistry changes. Now the sulfates are unstable and they react to form hydrogen sulfide, which is expelled from the exhaust pipe all at once. The high concentration is the reason for the bad smell! This effect is a common problem with new vehicles because the catalyst is working at a very high efficiency. However, as the catalyst gets older, the activity drops. Fortunately for us, one of the first reactions to be affected is the formation of hydrogen sulfide. So as the catalyst gets older, the smell will go away. It should also be noted that many catalysts never smell bad. One reason might be because the vehicle doesn't run lean for much of the time, or perhaps the catalyst has an extra component that reduces the production of hydrogen sulfide. "Next time Eggbert and Shelley stop behind a vehicle that smells bad, they can be grateful that it's at least not contributing much to atmospheric pollution." Thanks to this month's Whizard, Dr. Gordon Bartley, a senior research scientist in the Emissions Research Department of the Automotive Products and Emissions Research Division. Bartley specializes in the development, aging, and evaluation of vehicle emission catalysts.

check all vacuum hoses,a leak will cause erratic idling.also could be the throttle position sensor.plug a scan tool into the car,there should be a code,as to why the check engine lite is on.

after driving the car, pull off the vacuum line on your fuel pressure regulator and if there is gas that comes out the vacuum hose , your problem is a bad fuel pressure regulator!!! :)

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

• On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."
• On a V6 or V8 engine:
  • the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."
  • The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

NOTES:

• Use lots of penetrating oil - allow to soak - to make removal easier and avoid damaging the exhaust pipe
• the sensors are screwed directly into the pipe at a 90 degree angle and look like spark plugs with either 8", 12", or 14" wires attached to them
• Tools:
• ** ** it is usually a 7/8ths size wrench
  • special-purpose oxygen sensor socket - not expensive, and commonly offered for free use by the auto parts store
• Inspect the condition of wires and that they are not touching any parts of the exhaust system
• No special tool is required if you are not reusing the old sensor. Simply unplug sensor harness from vehicle harness then snip off the wires at the sensor. This will allow you to slip a 7/8" box wrench over the sensor for a tight, no slip grip for removal. Use the 7/8" open end wrench for installation of the new one.

NOTES:

Rule of thumb: Bank 1 is on the side of the engine with cylinder #1

6 Cylinder numbering:

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1 2 3

4 5 6

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Front of vehicle

Take those codes and research them on the internet! (see "Related Links")

A perfect example are P0171 and P0174 codes - indicate a lean mixture was read in bank 1 & 2 (respectively). On the Windstar, that's a prime symptom covered in Technical Service Bulletin TSB# 03-16-1 (see "Related Questions")

The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach

There are 4 O2 sensors on your Taurus. 1 is under each exhaust manifold and there are 2 just before the Y pipe. If it shows no. 2 on the scanner it is on the front side near the radiator. If it shows no. 1 it is near the fire wall - the side of the engine with cylinder #1. 3 and 4 are located just before Y pipe but I don't know which one is which. its located on the right hand side of the engine when you are facing forward with the hood up its located in the lower right hand corner Under hood, center, lower engine area, front side of engine, mounted in exhaust pipe .

Oxygen sensors are always screwed into the exhaust manifold as they sense the amount of oxygen in the exhaust and tell the computer how to mix the air fuel ratio. More or less.

just in front of the cat converter.. on each pipe... There are four (4)oxygen sensors on the 96 Taurus the two in the back are screwed into the tailpipe on both sides of the Catalytic converter. They are on the top of the pipe so hard to see, but you'll see the wires coming off them. The other two are at the front of the engine. the sensors are located on the upstream and down stream of the exhaust system..one under the car behind the catalytic converter and one just in front at the top of the exhaust system comming out of the engine block.where is #1 sensor located ?