2.8 V6 de-Cat, MOT emissions

[woodsyv12]

Hi Guys, can anybody help?, I have bought a 1995 2.8 coupe quattro which has been de-catted but now it's MOT time and the emissions are just a bit too high. Has anybody else had this problem and how can I get round it i.e. is there away of adjusting the fueling or can I trick one of the sensors to make the engine run leaner. I have already put in a new set of plugs and ran the car on BP ultimate for a few miles, this reduced it from 0.6 to 0.5 but I need 0.3. I tried opening a air pipe into the inlet manifold but the lamda sensors adjusted the mixture to suit. Thanks.

[jezza12v]

Hi, if the oil hasn't been changed recently then do so just before the test. Most of the nastiest emissions come from smeggy oil via the breather system especially on higher mileage cars, make sure the air filter is new also. (If desparate you can disconnect the crankcase breather and vent it to air but you must plug the hole where it connects into the intake). Some oils like 'Castrol High Mileage' are designed to reduce emisions. BP ultimate won't do the trick in a few miles, try an injector cleaner like Wynns or STP and do a tankfull of miles. I hope this is helpful.