I have a 2000 GU ZD30. It's always been good with regards to smoke, hardly anything! It's got a reconditioned motor in it with only about 12,000k's. My cat converter was dead so I've knocked out out. I'll be getting a new exhaust soon so it'll do in the mean time.
Since I've knocked it out, I've been getting a small amount of smoke while idling. Occasionally there'll be a bit while under load, but most of the time I don't see any. I find it strange that I only see it while idling.
I'm not sure if it's something else and just a crazy coincidence that it's only started now.
Could it be that the cat takes a bit of that smoke away or is there something else I should look in to?