2001 CL500 Running rich and lumpy after a cold startup

[Mikesmerc]

Hi Guys, my2001 CL 500 runs rich and lumpy for 30seconds after a cold startup. In the link below this happens between 20sec and 50sec on the video, black smoke can be seen by the eye at this time though not very visible on the video, after this it returns to smooth running. Any Ideas guys?
Ignore the noisy exhaust baffle

 

[mioba]

Standard answer, have you had the codes read or looked at live data,

Is the maintenance up to date, are the fuel and air filter good, have you checked the fuel hoses for leaks, could be air getting in the system whilst switched off and then once pressurised is normalises

Just some starting thoughts

 

[Mikesmerc]

I have read the codes, did come up with a faulty O2 sensor which I replaced, This car has been idle for quiet a few years, perhaps a blast on the motorway may improve things, Will check out the fuel lines. Thanks