Thanks Doc.. It wouldn't be so funny if it wasn`t true!
I`ll give you a quick example.. I needed to get a "smoke test" done in order to re register my SUV..
They put the probe into the exhaust and asked me to leave the engine running for 3 mins,which I did..
Everything was fine and my vehicle passed with flying colours..
I just wonder why they didnt notice that there was zero smoke coming from my exhaust due to the fact that the end of the exhaust was damaged and unattached from the muffler..
The smoke on my car is released just under the back wheel arch!!

Cheers,
Fred.