P0140 Astra 2.2 SRi

[SRiTez]

Hi all, I could do with a bit of advice. I fitted a new cat yesterday due to leak in the flex part, and because I couldn't get the second lambda sensor out I replaced that with a new one. Now after about 20 miles I get P0140 code. I've checked it with my op-com and it says O2 sensor bank 1 position 2. The sensor seems to be working ok showing between 447-455Mv. I didn't have any problems before I changed the cat and O2 sensor, so could it be a dodgy sensor or am I missing something?

Any help would be much appreciated.

 

[vocky]

is the new lambda connected okay, P0140 is normally a duff sensor or wiring

 

[SRiTez]

That's what I thought, it says open circuit so I thought I hadn't plugged it in properly or I left it to close to the exhaust and melted the wires. I can't understand how it can say open circuit yet still show 447-455Mv. I'll see what happens tomorrow when I go to work tomorrow.