John Etnier

I am getting frequent check-engine lights associated with the two knock sensors*. Performance is usually degraded when the light is on. I am trying to steer my shop in how to replace them: we have the manual printed out. Looks like a lot has to come off the top of the engine and the intake side to access these? Any input on this procedure much appreciated.

* I believe one check-engine code traced back to oxygen regulation, FWIW.

Eric_Oz_S2

You need to remove the fuel rail and then the intake manifold. The tricky bit is actually reattaching the dipstick guide tube bracket back to the intake manifold.

RajDatta

It's always easier to remove fuel rail and intake as 1 piece. Same goes when installing dipstick. Install the dipstick to intake 1st.

John Etnier

Thanks very much, gents. Much appreciated.

MB968

I just replaced the front knock sensor a few weeks ago on my 968. I did not remove anything to get to it. Maybe some of the comments above are for the S2 engine, or?. Toughest part was to find the right combo of wrenches/sockets incl a swivel joint to get it broken loose, and fully tightened when the new one was installed. You can't swing to tool through much of an arc, so it can take a little time. Before I installed the new one, I made sure threads were clean so I could easily screw in by hand.

sm

Would you use a Bosch knock sensor that can be bought at Advance Auto Parts with a 40% discount or go with the factory sensor?

RajDatta

They are both bosch parts. For the Porsche part, you pay extra for the box :P.