600SEL acceleration
 

Need help trying to figure out why I do not have the pin you to your seat acceration in my 600sel. My 400E has it, my 400SEL has it, but the 600SEL does not. Acceleration in the 600 is not too slow but I'm not pinned to my seat (literally) as I do in the other cars mentioned. Also, I'm constantly reading about how the 600 gets to jail time speeds in no time.

An indy pull codes a week ago and the only thing that came up were bad mass air flow sensor, bad idle control valve, and battery voltage issues. MAF was replaced which corrected the hunting idle and possibly the code thrown from the idle control valve. Indy said that the battery voltage readings are not much of a concern.

What should I look @ next that would not cause a code to be thrown?

If the air mass meter has been way out for a while then there is a possibility that the catalytic converter may have gone south and plugged up. There is one cat for each side so if only one is plugged then you would still have marginal power but not like you should. A backpressure test may be in order.

Not sure about the older V12's but the newer ones have a whole lot more than 2 cats. The M137 that replaced the M120 had 8 cats so I would assume the M120 has at least 4, if not 8.

When the air mass was replaced, did they reset the mixture adaptations?

The mixture adaptation was supposed to be reset. At least I was told that it would be reset because the shop was going to run diagnostic again to see if any additional codes were thrown.
In the even that the adaptations were not reset, how long will it take for the car to relearn with normal driving?

I think duxthe1 is right about the older car only having 2 catalytic converters... Had to have them replaced in a 600 that I sold not long ago and the cats were only sold as "Left" and "Right". But wow, 8 cats... a little off subject, but what is the benefit of having 8 cats? I was crying when I had to replace the ones in my other car because it was a dealer only part @ $1500; but, I decided to go with aftermarket ones that was half the cost for each... Can't imagine have 8 of them that could possiblly get clogged.