1999 S80 2.9 (NON turbo) Front oxygen sensors replacement

[lous80]

I have to replace the 2 front oxygen sensors. The car has 85kmiles.
I have the dash light on and a tester says that both have the heaters out. The car runs great otherwise and I think that it is because the heaters just give an added degree of precision vs a total sensor failure. That said I have to replace them and i was told that it is "easy" to do from the top of the engine. The sensors are somewhat visible, and it would be a great saver if i didnt have to remove the exhaust. I dont know if there is enough clearance to remove/install the units aside from the task of actual loosening.

[billofdurham]

I don't think it is that easy on the 1999 - 2001 vehicles.

Looking at VADIS you need to remove the centre member.
Remove the flange between the cat and the exhaust.
Unhook the rear mounting rubbers.
Support the cat on a mobile jack
Separate the rear exhaust from the cat, moving it back about 50mm (2").
Remove the screws from the front member and turn it.
Remove the screws from the front mounting.
Unhook the brake pipes.
Remove the clamps for the cable harnesses.
Remove the front member.
Lower the rear edge of the cat 120 mm (4.3/4").
Remove the heat deflector plate.
Separate the connector for the heated sensor and expose the harness.
Remove the sensor using a special tool. (When replacing the left sensor remove the left front wheel)

Installation is just about a reverse of the above but it mentions not replacing rivets in the front and centre members. I assume that you have to drill rivets out when you are removing them.

The sensors are tightened to 45nm.
The front and centre members to 25nm.
The exhaust flane to 25nm.
The rubber pads to 25nm.

I must point out that this is from VADIS and I have no first hand experience of changing the sensors on any model year of S80. It is possible that an owner has done this and has found an easier way.

Bill.