Checked out everything again yesterday, found a couple of slight probs but no improvement, however when I delivered the vehicle back this morning I hooked my gas analyser into the car and drove it back 3 miles of dual carriageway with it running 3000+rpm. Result was near perfect emissions- zero CO, >15ppmHC, 14%+CO2 and 0.5%O2 (leak in rear silencer)pulling up outside customers house I let it drop to idle- no change except O2 went up to 1.1% because of the rear silencer. Switched off and left it for 5 mins then no matter how long it fast idled the emissions stayed high-.8 CO etc. Do I just have a really naff Cat? Andrew