Reading live data on 02 Focus

[stoneringers]

Can anyone recommend a programme that I can do a live data trace on the oxygen sensors on my 02 focus. I have an elm cable. Many thanks

[teuton]

You can use digimoto V or/and Scan Master. Both here on forum.

[dannyuk89]

just test your o2 sensor with a multimeter or use obd code reader of ebay onli cheap

[oldford]

If this car has a wideband oxygen sensor in front of the catalyst, you can only use a scanner. They cannot be tested with a multimeter of even a scope.

[nutloose]

use an analogue voltmeter or a scope for all narrow band O2 sensors.
If you have a 5 wire wideband LSU4 sensor you could use the innovate LM1
(LM-1: Digital Air/Fuel Ratio Meter)

I dont think ford have wideband as std though

[oldford]

I don't know which O2 sensors are used by every make and model, but Honda already used them back in 1993 or 1994.

[stoneringers]

Thanks for all of your replies.
I am looking at a P0420 error on my daughters Focus (cat low efficiency). I wanted an 02 sensor trace to try to find out what is going on. I understand that the front sensor should vary between 0.2v and 0.7v and if all is well the rear sensor should be around 0.5v if the cat is working well and maintaining a good oxygen level. If not the rear sensor will track the front one. A crypton gas analysis basic emission test had the following results which would have passed an mot but I also understand that this does not mean the cat is good as Ford's emission rates are stricter than those for the mot
Fast Idle speed.
CO Level 0.05%
HC Level 9 ppm
Lambda 1.01

[oldford]

Code P0420 means the catalyst is not working correctly anymore. When you test it on a gas analyzer only a very small amount of gas passes the catalyst and it seems to be working. However, when you drive the car more gasses pass the catalyst and it is not working anymore.
Ford does not have higher standards then any other manufacturer. These standards are described in laws and regulations (EOBD-rules) which Ford has to obey.
How many miles has the vehicle done? Have there been problems with misfires? Like defective spark plugs, coils or something like that?

[stoneringers]

Code P0420 means the catalyst is not working correctly anymore. When you test it on a gas analyzer only a very small amount of gas passes the catalyst and it seems to be working. However, when you drive the car more gasses pass the catalyst and it is not working anymore.
Ford does not have higher standards then any other manufacturer. These standards are described in laws and regulations (EOBD-rules) which Ford has to obey.
How many miles has the vehicle done? Have there been problems with misfires? Like defective spark plugs, coils or something like that?

Thanks, The car had an after market cat fitted last summer when it failed the mot with emmision problems. This followed a coil pack failure earlier on in its life

[oldford]

After market cat's are known to fail new out of the box.
You need to fit a new genuine cat.

[teuton]

You can check your cat. converter using an I/R thermometer. With cat working tthe outlet temp. should be some ~50 deg. Celsius higher then inlet temp. If inlet and outlet temps are similar or same, then the converter is clogged. If inlet temp is higer than outlet the converter isn't working anymore.
So basically you're looking for a measurable temperature change. Test conditons are engine warmed up and idling. Higher reved up engine will produce higer exhaust temps., but the overall difference shouldn't change a lot.
HTH.

[nutloose]

cat efficiency faults are set when the post cat sensor switches nearly as fast as the front sensor.

pre cat sensor switches about once per second.
post cat switches about once or twice a minute (good cat)