Hi guys & gals,

I've recently bought a 2002 Merc C-180 W203, non-kompressor model, with 80'000 miles on the clock. It was idling rough when i got her and had very poor fuel economy, also a few days later it threw the P0130 and P0131 codes at me. Anywho, bought a brand new VDO Siemens MAF sensor and a brand new Bosch O2 sensor and installed. Running much better, better fuel economy and CEL has not returned.
The only thing is that the car is still idling slightly rough on first start up, only for about 30 seconds then it smooths out.
Is this normal or am i missing something? I know Toyota's have a higher idle when cold to get the engine warm but this surely isn't enough time on the C-180 to do the same?
Would spark plugs be a factor? I pulled mine out and noticed they were a bit past it looking, only the basic copper core NGK's were used by the previos owner.

Any help would be very appreciated