Hi guys, have a 1997 w140 s600 that seems to lack power, acceleration isnt as sharp as it used to be. Idling is ok, no shaking or obvious roughness but subjectively is not as smooth as before.

First I had it scanned at an indy shop. Relevant engine faults were:

p0300 misfiring
po312 (?)
p0170 right cyl mixture adaptation reach limit value, current
p0173 left cyl mixture adaptation reach limit value
p1146 no fault text specified (found out this is left hot film air mass sensor)
p0410 secondary air injection malfunction chain (?)
P1444 no fault text specified (found out this is left cat converter temp sensor)

erased, drove it around, scan again, results are:

P1444 no fault text specified (found out this is left cat converter temp sensor)
p1146 no fault text specified (found out this is left hot film air mass sensor)
p0170 right cyl mixture adaptation reaches limit value, current

Indy shop lacks expertise to interpret and suggests I go to dealer. I searched the forums here before going to get ideas.

Had a short test done at dealer the next day, relevant engine fault codes are:

p1444 left catalytic converter temp sensor (b16/4)
p0170 B Self - adaptation idle speed at right limit value (n3/12)
p1146 left hot film air mass sensor (b2/6)

erase codes, drive around block, scan:

p1444 left catalytic converter temp sensor (b16/4)

I was ready to conclude AMMs but they didnt come back on the 2nd test at dealer.

in my forum search stevebfl mentioned that a failing air mass meter causing weak throttle response off idle so i took a look at the actual values.

self adaptation part load factor right - 1.22
self adaptation idle speed right - 0.6 ms

With this fault history and actual values would it be safe to assume failing left and right AMMs at this point? Anything else I should look at to confirm?