well I removed the pre cat the other week and since then my o2 sensor on bank 1 has gone down. What effect will this have on the running if the car and what will have been the most likely cause.
I think what may have cause it is when I was cutting the pre cat out I used W40 to help cool and lube the hole saw and cat. Think it may have swarfed up, is this is the case would removing it and cleaning it cure the fault?
Also does anybody happen to have a spare second hand one kciking around for little money. Have a 500 mile round trip at the weekend and think the economy on the car is suffering.
Cheers aqll.