[JGriff]

Looking through all the receipts on my recently-acquired 1990 944 S2, I did not see a receipt showing the O2 sensor being replaced. (I am planning on contacting the PO just to make sure.)

My car now has 75k miles on it. What is the change interval on these cars? Usually for most cars, it is 60k miles.

Should I change it now, just to be safe, and to make sure that the car is running properly? (Usually, O2 sensors degrade slowly over time, and the performance loss is usually not drastically noticeable... is degrades slowly as well. I want to make sure that the car is at peak performance.)

How easy is this to do? Is there a post here somewhere (I did a search, and found a lot of discussion about cold air intakes, lean/rich problems, but nothing about replacement), or a web page with pictures and procedures on how to replace one on an S2?

I've replaced the O2 sensors on my Audi... so I'm not afraid to do it myself... I just need some general BTDT advice etc., since I do not have a repair manual for this car yet.

Thanks in advance.

Happy New Year!!

Jim