I have a 99 clk 320. How can I remove front right oxygen sensor (passenger side before catalyst)? Should I access it from bottom of the car? Can anyone point me to right direction?
Thanks
Bobby

OK. Got it. One could access it from the top after removing air intake tube.
So I did replace the O2 (Bank 1 Sensor 1) but the car still has rough idle and shakes even more when I turn the AC on.
I did scan for code and I am getting P0173, P0170, and P0130 (pending). The scanner does not clear the codes and it kept saying: Command sent 3 codes remain.
Before changing the O2 I did:
clean MAF (no go)
Replaced the MAF insert (no go)
Note: I bought the MAF insert from ebay which I think is generic one since it does not indicate the Bosch brand.
What do you guys think? Any Help?

you might have a clogged egr tube or bad egr valve. On my car, the tube was clear but the valve went bad.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

Thanks for reply
Is there a way to check egr valve and tube or should I just replace them?

Update:
I just changed the 2 motor mounts and the transmission mount. Rough idle is gone and the car does not shake anymore. P0173 and P0170 codes are still there.

usually the tube gets cleaned; the valve may have to be changed. do a search in the ml forum-the ml320 had the same engine & the techniques are described there.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

thanks.
im trying to remove the egr tube. but for some reason i cannot. i did remove the 2 bolts which connects the tube to intake manifold. do i need to remove the egr valve first?
btw, i did search the forum and could not find how to remove the tube.

ok. i did manage to remove the egr tube by opening the bolt between the tube and valve first.
the tube was clear.
is there anyway to check the egr valve before replacing it?
does the bad egr valve results to P0173 and P0170 + cel?