I have got a 2007 Opel Vectra GTS 2.2 Direct car (which still has a high pressure fuel pump problem, yet to be solved). Petrol, 114 kW, engine Z22YH.
After getting an P0130-52 (No Plausibility between O2 Sensor 1 Bank 1 and O2 sensor 2 Bank 1) error, I started monitoring voltages of O2 sensors (via Opcom). One which is pre-cat was about 1.5 (up to 2) volts on idle. I've been told that lambda probes should not give more than 1 volt, so I've decided to replace it. Now it shows 5 volts. The ECU does not give any errors regarding that. In case of revving up, I get the same P0130-52 which seems to be because of the same high pressure fuel pump problem. The fuel mix seems to be always rich.
I've ordered a new pump, but I don't know if is it safe to replace it while this problem exists.
I'm quite new to cars, sorry.