I have a Porsche Boxster 2.5 and it has failed the emission test on to high Co. The car has been serviced including fuel filter, plugs, oil, air filter, oil filter and coil packs. In addition to this its had new Cats, new o2 senors and I have cleaned the Air flow mass sensor. There are no error codes coming up, have you any idea why the ecu is providing to much fuel so its pushing up the Co emissions? I have cleaned the air system and I have mixed the petrol with injector cleaner, could this cleaner affect the readings? Please can you help? Thank you
