why my rover is high on co 2?

Question

failed m o t on high co 2 (new engine)

Answer 1

faulty lambda sensor faulty catalytic converter

This is a really useful site by the way

http://www.mg-rover.org/

Answer 2

The most probable is the Catalytic converter, I had a faulty Lamda sensor and my MGZT still passed the MOT. Its the Cat that cuts the CO2 emmisions so that would be my first choice. What year and Mileage ?

Find the MG and 75 owners club on the net and ask in thier forum, you will get an answer very quickly or the Rover forum. Ask Jeeves he will point you to them.

Answer 3

CO2 isn't a testable item during an Mot. CO2 (Carbon Dioxide) is a byproduct of the catalytic converter. CO (Carbon Monoxide) is testable. Various things cause it but a good high engine speed (that's engine speed, not vehicle) just before that test normally gets the catalyst temperature up enough.

Answer 4

Can't have been CO2 (Carbon Dioxide) - that's not an MOT requirement.
High CO (Carbon Monoxide) is an MOT failure.

Could be lambda sensor failure, or catalytic converter failure, or just an incorrectly programmed ECU (is the new engine exactly the same as the old one? Was the ECU changed / reprogrammed if they are different?)

Take it to a garage with the correct testing and tuning equipment.

Answer 5

Did someone use an additive octane booster in the fuel? That will wipe out the catalytic converters and raise the CO² levels.

Answer 6

is the engine tuned right as u said it new engine has the ecu been programmed for that unit

Answer 7

have you given her a basic service? if not try replacing air filter oil and oil filter, i have known this problem a lot.