need help with air/fuel mixture problems

[CrisZenithBlue]

I'm still a bit confused about the O2 reading a flat value..
is it the O2 sensor that's dead or the cat?

maybe an easy way to find out is to switch the left and right O2 sensors and see how they read? those damn sensors are about 100$ a pop..

[bwdz]

Originally Posted by CrisZenithBlue

I'm still a bit confused about the O2 reading a flat value..
is it the O2 sensor that's dead or the cat?

maybe an easy way to find out is to switch the left and right O2 sensors and see how they read? those damn sensors are about 100$ a pop..

That is a very good idea. Also you can test with a voltmeter. O2s actually produce voltage, it is not a signal from the computer and then a return signal like other sensors. You have the heater wires but the 2 white wires should produce voltage and you can verify that way if it is the o2 or if it is a wiring problem. I work on a lot of cars and keep plugs off old o2 sensors and scrap cars o2 connectors with extended wires so I can just plug into it and test it in a convenient location rather than underneath the car.

[Nine8Six]

How do you ensure its within the mV rated range? Fluid sensors needs a pretty sharp resolution to function to specs, no? Was under the impression only a computer was geared for this sort of accuracy. Mind you if one have a industrial grade multi-meter then it might be doable. Really dunno... excuse my ignorance on the subject, never done it. Interesting stuff

Warning: requires 10 mega-ohms independence multi-meter on Porsche cars (and Prius). To prevent drawing too much current and damaging the other end, something like that

Porsche are complex things! Love it tough...

[bwdz]

Originally Posted by Nine8Six

How do you ensure its within the mV rated range? Fluid sensors needs a pretty sharp resolution to function to specs, no? Was under the impression only a computer was geared for this sort of accuracy. Mind you if one have a industrial grade multi-meter then it might be doable. Really dunno... excuse my ignorance on the subject, never done it. Interesting stuff

Warning: requires 10 mega-ohms independence multi-meter on Porsche cars (and Prius). To prevent drawing too much current and damaging the other end, something like that

Porsche are complex things! Love it tough...

You won't get "accurate" readings with just a simple voltmeter. You can however determine if it is "dead" if you get something similar to nearly no voltage that his scanner is reading. It is a little easier to do on the secondary o2 as it's voltage should be much steadier than the fronts. If you have a fancy meter or a scope or even a high low min/max meter that is a little better. All the reading should be done after the car is warmed up, the heater circuit can malfunction on the o2 and cause problems as well.

[CrisZenithBlue]

to conclude this old thread:

plot twist! i had the wrong version of MAF. i got this on Amazon and has been working flawlessly for 2 years: Bosch 0280218009 Original Equipment Mass Air Flow (MAF) Sensor