The Pico TA018 current clamp can either be purchased as an accessory within one of our popular diagnostic kits or individually under the packing code PP264.
I am duly educated thanks Martyn. I did not realise that you were using two part numbers for the same component. I only know it as the TA018.
I think the difference between the two clamps is the leads ends, one is BNC and the other I think is male leads ends like voltmeter leads.
STC wrote:Steve smiths case study works a treat. An easier, quicker & less detailed method is to ac couple the signal wire and you can see rich or lean which is enough most of the time.
If you really need to know how rich or how lean then you can graph the data on a good scan tool and that will paint a reasonable picture, of course that is slow serial data not as raw or as accurate as the Pico will show
Kim has put a lot of good effort into her research there, which ill take me some time to read through it and properly understand it. But thanks for the link and advice.
All the response-reports on this thread are just about right Imvvho
You can research the K110 clamp and it is as good as reported. I merely stated it's accuracy against a posts uncertainty towards general amp clamps abilities/accuracy.
One thing to remember with the AF wideband sensors is, if a fault code (whichever manufacturer) shows up for that sensor...... its more probable than not the AF wideband sensor at fault, go ahead with almost total certainty it's at fault as reported by the fault code. Therefore, in the case of testing AF Wideband sensors, there isn't 'really' a need to. (This obviously excludes associated wiring)
The AF Wideband sensor is one part I'd happily replace without further costs in proving the fault.
if a fault code (whichever manufacturer) shows up for that sensor...... its more probable than not the AF wideband sensor at fault
Agreed, it is one area where you can almost guarantee that a new one will fix it.
But, when we need a known good for analysis for example a misfire amongst other things then it is essential to know what is being emitted by the engine pre catalyst. that is the hoo haa behind wanting to measure the signals from these things.
if a fault code (whichever manufacturer) shows up for that sensor...... its more probable than not the AF wideband sensor at fault
Agreed, it is one area where you can almost guarantee that a new one will fix it.
I was going to say something earlier about this but felt I should withhold in case somebody should kick my legs from under me , however following on from the post quoted, where a wideband sensor is suspected of a fault, it has been proven in times past that actually unplugging the sensor and running the engine will actually prove/disprove if the sensor is the cause of the problem.
A VW Polo with a 5 fire wide band sensor, bank 1 sensor 1 had a pump fault, the sensor was signaling the PCM to increase fuel causing a serious rough and rich running engine, unplugging the sensor allowed the engine to run smoothly. After replacing the sensor and clearing the code the engine was found to run satisfactorily. It's not the correct test procedure or the right way to check it, but a rough and ready method, which is why I started the thread to ask about equipment for correct testing.
Agreed, it is one area where you can almost guarantee that a new one will fix it
Perhaps that should read
Agreed, it is one area where you can almost guarantee that your testing will prove it has failed and a new one will fix it.
The same can be said of NOx sensor codes, P0420 Catalyst....
It's not the correct test procedure or the right way to check it, but a rough and ready method, which is why I started the thread to ask about equipment for correct testing.
If you are looking only to test the O2 sensor then you dont need any fancy equipment, OBD actual values whilst you promote change is normally sufficient, if you have a scope then that is miles better, you can just ac couple the signal, or with a Pico there is vertical zoom - even better. Better still Steve Smiths tutorial with a math channel.
In your case with the Polo i'm guessing Obd data would have shown it stuck lean with little possibility of forcing it rich ? Unplugging it should have given you additional open circuit fault codes (some confirmation of wiring) ?
and lambda would have sat at a default value. So yours is not necessarily the incorrect test procedure, it has some elements of a good one
Now, if you have a different fault and you are looking at a good O2 for clues as to the chemistry/quality of combustion, lean misfires .... .... .... in that engine then that is where you need real time accuracy. The micro Amp Clamp will be good and quick, a straight forward voltage reading of the signal wire may have a marginally faster response rate on the screen.
Picokev sums it up very well in his post.