exhaust gas emissions

hi
i have a 2000 multipla 69000 miles 1.6 elx which has given faultless service for the last year, but has now failed mot on exhaust emissionswith a reading on co of 76% when it should be below 30%. ive had a new middle and rear section of exhaust fitted and am now at a loss as i was told the old exhaust with a hole in was the cause of the high reading. i wonder if any one has any idea what may need replacing in order to cure this problem before the garage fleece me for all my money.


pleasse help me keep my beloved multi

now ive fallen out of love with this car, just had a krypton tuner out to have a look and his expensive diognostc equipment will not connect to the car. so it looks like its of for some expensive work at a main dealer.

car now in local fiat main dealer, diagnostics appear to have told them nothing as to what is wrong so they seem to have gone into guess mode. thats something icould have done my self for free just replace everything one at the time until i find the one that fixes it. they have said a new cam belt at £300 and a lambada sensor at £120 plus £67 for the diagnostics and none of them may work as it may be the cat at £500 + labour. when i git the car it had quite a bad misfire on acceleration which turned out to be a perished ht lead on no 1 sparking on the engine and when the battery died on holiday last summer the car was push started 3 or 4 times would these two instances be enough to screw the cat and would i be better just getting that changed.
any suggestions would be much appreciated.