HELP Please

[Pyros6546]

well just had my 6 in for mot and what it failed. on emmisions the co2 was reading .65 to .77
took it to local pug specialists there computer could't establish a connection to the ecu so
can't find out if theres anything wrong with it, they said to take it back tomorrow when they
get there big computer back. was just wondering if any of you guys know whats up and
the approx cost of repairs its a d8 2.0glx 16v on a 1997 p reg. oh and one other
thing it did whislt it was idling in test centre was rev up to 3000 with no one near the car

[Pyros6546]

surely someone has an idea

[jameslxdt]

theres no point reading the fault codes as the engine management on your car is too stupid to realise if there is a problem

i think you mean your CO, carbon monoxide reading was 0.65 to 0.77, as CO2 is a product of efficient combustion and you should get a reading of arround 14.7% upwards

there are a few things that could be causing the reading to be out, though i would first recommend some forte injector cleaner and a 80mph blast in 3rd gear down the motorway, then go straight for the test, as that is only slightly out, did it fail on fast idle or the natural idle test?

[Pyros6546]

it failed fast and natural idle, then the pc came up with rpm too high
was running at around 1020rpm wouldn't drop took the guy half an
hour and a lot of messing to get it calibrated again but still failed
was on a long run sunday didn't show any probs or any excessive
fuel consuption and yes i did blast it a little have had redex injector
cleaner in it for the last 6 refils of the tank

Update 31/5/07
had the 6 to stealers to get diagnosis from there tests
it was change by the previous owner last yearit appers
the cat is faulty, which is strange considering. but if
it cures the co i don't care

[Pyros6546]

good news i got the 6 through its test
was the cat that was faulty, now i seem to
have another problem whilst it was stood
idling it reved itself up to just below 3000rpm
any ideas what might cause that