Engine knocking sounds... Please help!

Hey everyone!
I really need your help guys! Many times I posted my questions on BMW forums and always got the right answers.

Anyway, here is the video where you can hear these strange knocking sounds coming from my 325i 2002 engine:

It started yesterday after I changed the oil, oil filter, fixed valve gasket sealant, changed a boot on first coil and changed all the spark plugs.
The reason I had to open up the gasket is because I had a very bad oil leak into the first coil compartment. Turned out, my last mechanic did not properly place that rubber sealant piece on first three coils. So I fixed it and no more oil there now. Initially the car was misfiring really bad, so I thought that was the problem.

However, now the car misfiring even worse I got the denso irodium sprak plugs from Advance Auto Parts... They said that Bosch were discontinued (weird). Anyway, they told me that the gap in spark plugs should be 0.44, but then I found on the net that it should be only 0.32... I tried both combinations... But still a bad misfire and knocking noise.

And these are the codes that I have:
P0300
P0174
P1085
P1083
P1349
P1353
P1351
P0420

If you anyone had the same problem, please share your experience!
Thanks in advance!

You`re running the wrong plugs, which has been known to cause problems. NGK BKR6EQUP are OEM-spec, try those. The noise might be a detached flap in your DISA valve.

On my way to exchange the damn spark plugs! Let's see if it do any better!

Changed the plugs... but didn't do any better :/ One guy said that it is back firing... What can be the reason for that?