Hi to All,

I have the check engine light coming on and off on my SL500 recently.
I had the fuel filter, air filters and spark plags replaced last month.
It has 91K miles on it.
I had the car scanned today, and had the following codes stored:
PO305, PO306, PO307, PO308 (cylinder 5,6,7,8 misfired)

Also PO150 which is a front oxigen sensor in bank 2. I like to know if that is the driver side as I was told or not.

Also PO300 which is a random misfire and PO410 which is a malfunction in the secondary air injection system.

I was thinking about to have the driver side oxygen sensor replaced first.
Can that cause the misfire? What else should I have checked?
One more thing I should mention. If I floor the gas padal, it looks like half the engine shuts off and loose the power. If shut off the engine and restart, all cylinders are working.

Any help would be highly appreciated.

Thanks!