How many miles does your car have? As a general rule if you are over 100k (miles) then you probably need to inspect the cam chain tensioner and replace if necessary.
After having done the job I am not convinced there is any reason to replace the entire tensioner assembly. I think that was only necessary before the individual pad was available from ZIMs. This job obviously requires removing the cam cover, so you will want to have a new gasket as well. I would only recommend you try this if you have a fair amount of technical knowledge - the tensioner assembly gets a bit complicated and is covered in oil - beware small washers! A torque wrench with a low range is also necessary if you want to get the cover and tensioner bolts correct - 7lbs!
At 115k my upper tensioner pad was developing a serious crack. The lower was fine and the tensioner assembly was in great shape. I also inspected the chain carefully. Entire job took several hours but I was very methodical. Lots of small parts.
There are several good threads on Rennlist that detail the procedure and 944 S2 Central has a good procedure although it is sometimes unavailable
944S2 Central
I am convinced that this is not something that 16 valve owners can put off. After looking at the old pad I was relieved to know that my engine was not longer relying on it.