Marvic

Guys any tips on replacing the downstream oxygen sensor? The passenger side is easy to access but the driver side is a little bit hard due to the drive shaft blocking it. Any tips?

Thanks in advance!

chassis

@Marvic One idea is to remove the left catalyst as a unit. In principle it seems straightforward. Likely need impact tools and may have to replace fasteners if rusted.

Another idea is to remove the front driveshaft. The attached gives torque specs and tightening sequence.

See attachments.

Part number A0045420718 Lambda sensor, item 130 in the diagram.

p.s. VIN is from a vehicle on Cargurus, 2007 GL450.

Marvic

Is there a way not to touch the driveshaft or the catalytic converter?

if there’s no other way whats the easiest? The drive shaft or the catalytic converter?

thanks in advance!

chassis

@Marvic MB gives no instruction on removing the downstream sensor individually.

I looked at my W166 from above and there might be access if the bulkhead “paneling” is removed. I haven’t checked from below, but to me removing the front driveshaft doesn’t seem so bad.

Marvic

Good afternoon guys,

just an update I was able to replace both of my downstream sensors using only a 22mm open wrench. I had enough room to wiggle through the spaces. Thank you so much for the help and advice!

chassis

@Marvic Glad you got it solved. I crawled under my W166 today and the downstream sensor looks remove-able in my opinion, not sure how different it is from the X164. Onward and upward!

Marvic

yup it was a tight space but I was able to maneuver the wrench to get bank 1 & 2 downstream sensors out. Now next will be putting some running boards.