I had identical fault two weeks ago code p0130 is o2 sensor voltage low, it is being logged because of a weak mixture. A new MAF sensor cured the fault. To confirm it check the MAF sensor on a scope with 5-10 seconds timebase accelerate briefly to full throttle & watch the response. The old sensor peaked at 3.5 volt taking about 2ms the new one peaked at 4.25 volt taking 1ms Bosch do the same sensor far cheaper than vauxhall