Thread: Open Loop all the time - stuffed O2 sensors?

Hi all 02 D2 V8 with an LPG converter that relies on the left bank O2 to adjust mixture. It has just had a full overhaul kit put through and its almost sorted, but the economy could be better and at idle it could be better - I think I know why, because the O2s seem to be out to lunch (cheap made in China jobs that I got off e-bay a couple of years ago) - my scanguage II shows open loop all the time, even when hot. New MAF a year ago. I programmed the X-Guage so that it reads the O2 on each bank and it seems to react quickly enough with a wide range of values and seems to do so evenly...yet the guage says open loop all the time from dead cold to hot...and the scanguage shows the water temp going up to 92 degrees C etc so the vehicle comp correctly records the water temp.

I think the best thing to do is stick some german Bosch O2s in (first I will clean the connectors and earths for the O2s) - can anyone recommend a supplier.

Any ideas why the 02s seem to be cycling and doing so evenly but she is open loop...I assume that they have evenly worn out after a couple of years...they used to correctly show open loop when cold and then go to closed loop hot.

Cheers

I would be suspecting your scan tool. They are as only as good as the program with in them. The fact that your O2 sensors are cycling like you say they are, tells me the ECU has feed back and fueling control. Therefore it has to be in closed loop.
If it was truely in open loop there would be no fuel control so you would not see the sensors cycling a rich lean mixture.
To have the sensors cycling means the ECU is controling the fuel supply by monitering the O2 sensors, closed loop.