I asked this question earlier but didnt add my yr or make, Is it my O2 sensor or cat converter?

Question

Check engine light came on. Code said problem was on the 2nd bank. Mechanic told me he wasnt sure if it was the O2 sensor or the cat. After a week Check engine light went out. A month later, now its back on. Went back to get it checked and they told me the same thing. Which one could it be? It doesnt have alot of power like it should. Everything else seems to be running normal. No rattling on the cat or no glow. So what do you think it could be? It is a 96 Ford Taurus V6. Gas mileage really hasnt changed. Thank you for all your help!!!!

Answer 1

I have no clue, but wanted to point out, that you could even include even more info. I have a 96 Mercury Sable (Taurus' sister). My check engine light has been on for over 2 months now. I took it to Auto Zone (auto part store, maybe you have one in your town?). They will tell you, for free, what the diagnostic code is. That code would help.

For example, I have a code P0340 on mine.

All the codes are listed at:
http://www.obdii.com/codes.asp , but i'm sure there are other sites that will tell you the codes too. Just google "Ford Trouble Codes OBD".

Anyways, by googling the code I got from autozone led me to that site, and eventually an article about the code: http://www.obdii.com/ubb/Forum1/HTML/001446.html

The code refers to: Camshaft Position Sensor Circuit Intermittent. Ok, so I figure out my camshaft postition sensor circuit is off. I have full power, there are no misses. It pearls like a brand new Cadillac and will lay a patch when i step on the gas, even on the freeway. No problems with the car whatsoever, but the error code displays always. Anyways, after googling a ton of stuff, I eventually have several people saying that this code was attributed to a bad alternator. The alternator is fine, but some partial short circuit fooled the computer into throwing this code. I believe that is true. My alternator seems to make a mild noise, especially when its wet outside. The car runs fine, but by googling the code number, I kind of figure this is probably true. Until the alternator completely gives out, i'm gonna keep driving it as is (going on 2 years now and it still pearls like a Caddy).

So, I'm just saying, try to get the code number off the diagnostic equipment the mechanic, or your local Autozone (or maybe another auto part store will hook up the OBD scanner and get the code). Then post that, and while you waint on an answer, google the code number.

Answer 2

Mechanic 9yrs<<< Before I get into the problem let me explain something for everyone related to trouble codes. Do not take your car to auto zone thinking they can tell you what is wrong with your car. You may read a code related to the o2 sensor but, that does not mean that's the problem. It takes testing of the suspected problem before determining the source. Example would be a code related to a throttle positioning sensor. Mechanic would test the tps with a multi meter to be sure! Another example.... I had a customer about 4 years ago with an older Chevy Berretta. He used a trouble code scanner which, showed 3 different codes related to ignition timing, temperature and, 02 sensor. After testing various things I found one problem. A faulty EGR solenoid. Trouble code scanning gives you a ball park starting point. Nothing more!

The computer tells the air/fuel mixture by the 02 reading. If there is a problem and the computer cannot lean the engine out enough to compensate then it may see it as a faulty 02. Does not mean it could not be a bad fuel pressure regulator, throttle position sensor, on and, on.... Do you see the picture? In my years of working on fuel injection I have learned one thing very quickly. Code readers are like fortune tellers. They sound great but really are full of #$%^!! Even a broken clock is right twice a day! Get a real mechanic to find the problem.

http://lessgov2007.blogspot.com/index.html

Answer 3

It's real hard to give an answer without the code their is more than one code it could be Bank One Sensor 2 Htr Crkt Lw signal or other without knowing this it makes it hard to diag over the Internet. Just something to remember an exp mechanic can make an educated guess of the problem with more information like code and any problems.

Answer 4

The ECM (computer) compares the front and rear O2 sensor readings to determine converter efficiency. That is probably why the CEL (check engine light) came on. The best clue you gave was that "it doesn't have alot of power..." Now that is a classic symptom of a plugged converter. Without being able to run further tests, I'd bet on the converter.