How to replace O2 sensor in 99 9-3

sensors for my 1999 9-3S and am hoping I can install them myself since our dealer wants to charge me $850.00 for the job. Any help?

Shouldn't be too difficult. Take off the aly shield over the manifold and you should be able to see the front one. The back one is at the bottom of the down-pipe, should be visible from under the car. Torque is 55Nm for both but you'll need to guess that with an open-ended spanner. They both plug in under the throttle-body cover. The back one has a bit of a tortuous cable-route so tie a bit of string to the connector before pulling it out so you can use the string to pull in the new cable.

Cheers,

Colin.