O2 sensor OEM or aftermarket

halo2 guy wrote:
> Here in Washington they don't even run a tailpipe test on the OBD II cars,
> 96 and later. They just scan the computer for any trigger codes and if
> there are none you pass. I actually prefer to see what is coming out of my
> pipe.

here, they do everything. put the car on a dyno, plug the big smog
computer into the OBD2 port, check for codes, test at 15 and 25mph, test
the gas cap pressure.

An interesting note: Bosch invented the o2 sensor and the first car to use
them was Volvo in the late 70's.
As long as the 02 sensor switches at a decent pace and the numbers go from
high to low, there isn't much more that it can do. IF the car is running
rich (high voltage) or lean (low voltage, then the o2 sensor starts hanging
around those numbers then the ecu starts adjusting the injector pulse to try
to correct the problem.
Our shop Forman worked for Nissan for years and was "the problem solver "
for northern cal (when he lived there) and Oregon in the more recent past.
He told this story: A Nissan 300zx 6 cyl. drove fine around town, but when
the once drove out of town at the 50 mile range the car would start to run
like sh*t, as the owner said "on 3 cylinders" So my boss took it on a drive
and sure enough at the 50 mile range it started running bad. He had a Nissan
specific computer hooked up reading all the data, he noted that 1 bank of
the car's 02 sensor was reading 2 volts! the car was trying to correct the
o2 sensor by shortening down the 3 injectors pulse width until there was no
fuel coming out, and the car was running on 3 cylinders. He had to
disconnect that 02 sensor to get the car to run to get back to the shop. He
called the higher ups at Nissan to tell them what he found and was told that
it was imposable for an 02 sensor to get above 1 volt, so the sent them the
computers saved dada on the test drive.


--
Stephen W. Hansen
ASE Certified Master Automobile Technician
ASE Undercar Specialist


"Randolph" > wrote in message
...
>
> Steve wrote:
>>
>> You can Blame the o2 sensor, but what else is wrong? Regardless of what
>> brand they are they work on the same principal, and the numbers won't
>> effect
>> the economy unless dead or off. here is something I wrote concerning this
>> subject.
>
> I would agree that the brand of O2 sensor is not responsible for the
> increased fuel consumption. The transfer characteristics (the
> relationship between oxygen content in the exhaust and the output
> voltage from the sensor) of O2 sensors vary widely. Some are virtually
> digital, i.e. the voltage is high (~900mV) when the O2 content is below
> a certain threshold, and low if the oxygen content is higher than the
> threshold. Other sensor have a fairly linear response around
> stoichiometric air/fuel ratio. If you get the wrong type, I can
> certainly see that fuel economy would be affected.