Hi all

My 87 560sl has just passed the local emissions test (yea) and runs fairly well.
I've also just done a tune up - new plugs etc etc.

My question is regarding the oxygen sensor.
The records show the last owner replaced it about 60, 000 miles ago and I' wondering if, from a maintenance point of view, if it should be replaced even if it seems that all is well?

I wouldn't complain if the mileage or power were to improve but don't want to pay out bucks unnecessarily.

If the answer is yes, whats your opinion of aftermarket non MB sensors?

Thanks in advance.

Barrie