Help Please!!! My C43 has a cold

[JoeFrankC43AMG]

I had a post a while back about a check engine light that come on intermittently. Well, finally, I had a chance today to go and get it checked out on an OBDII scanner. There are a lot of problems.
Here are the codes that were pulled:
P0130
O2 Sensor
Circuit Malfunction
(Bank 1 Sensor1)

P0161
O2 Sensor Heater
Circuit Malfunction
(Bank 2 Sensor 2)

P0301
Cylinder 1
Misfire Detected

P0304
Cylinder 4
Misfire Detected

P0303
Cylinder 3
Misfire Detected

P0300
Random/Multiple
Cylinder
Misfire Detected

DTC Pending (codes)
P0135
O2 Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1)

So that about sums it up. I want to fix this myself. What should I do? Where do I get started? Should I just take it to the dealer?

Also, for some reason, the windows go down and the doors unlock themselves randomly when it is parker and locked. The doors also unlock themselves sometimes when I'm driving and hit a bump.

If anyone has any suggestions please get back to me they would be greatly appreciated.

The car is a 1999 C43 AMG with 97k on the clock.

I worked on all my previous cars, but have not done anything on this one as of today. I can do a reasonable amount of work, but if there is a chance I could really screw up my car, I would rather take it to the dealer. Otherwise, I like to think that I am competent.

Thank you!!

[jnenad16]

wow.
judging by the codes, it clear that the O2 sensors are out since the heater circuit code popped up. now, if you had the codes that just described misfires and O2 sensor implausible signal, I would suggest you have a vacuum leak or a dirty/failing MAS, but since the codes also describe the heater circuits, my guess is the oxygen(O2)sensors are dirty, so get those replaced. your car has 4 of them, and three of them are getting a fault code.

nenad