anti pollution?

i have a peugeot 307 style my anti pollution came on last year on my warranty 3 time it took to correct the faults firstly nothing wrong with it but the lights came back on in the end the paid for a new ignition coil and spark plugs and engine ecu down load and all went away he presto its back but the warranty is out of date this time £80.00 diagnostic test and a further £276.66 internal fault for bsi unit and labour charge £100