hi all i have had a problem with my veccy for quite some time now emission light keeps on coming on and off i had the rac diagnose it for me and it came up with 2 error codes the first was po100 and the other po170 i think the 170 is the fuel trim bank 1 and the other the oxygen sensor is this gonna be expensive as its booked in at vauxhall next week also its very sluggish and from cold it feels like im pulling off in 4th gear