JCGMS

This weekend I changed the O2 sensors on my 997, a relatively easy job.

While the generic process of replacing sensors on is well documented in many places there is little info specifically regarding access to the sensors on 997.1 3.6L cars.
https://rennlist.com/how-tos/a/porsc...sensors-383523
https://rennlist.com/forums/997-foru...placement.html
https://rennlist.com/forums/997-foru...placement.html

Some notes:
1. The wheels, rear bumper, mufflers, and exhaust components do NOT need to come off. Airbox removal is necessary.

2. My car needed to be lifted slightly in the rear. This may not be necessary for all as my car is lowered.

3. Tools: A long 22 mm wrench was really all I needed. A flex-head ratchet with O2 sensor socket came in handy for the tightening driver’s side post-cat from above but was not absolutely necessary. Flat head screwdriver to remove the airbox.

4. To reach the sensor plugs you need to remove the airbox. Note that the 3.6 cars don’t have a resonator so all you have to remove is the MAF sensor plug and pull off attachment to throttle body (you can skip steps 1 and 4 in the Rennlist link). This is also good time to change your engine air filter and clean your throttle body.

https://rennlist.com/how-tos/a/porsc...-filter-383520

5. Once the airbox is out you will have access to the O2 sensor wires and plugs on each end of the engine bay. The pre-cat sensors have a blue sheath, and the post-cats are grey. You need to pull the blue sensor out of its holder before you undo the plug (spread the little plastic posts apart and pull up). The grey ones can stay in place while you unclip them.

6. All 4 sensors can be reached from under the car with a long wrench or ratchet. The pre-cat sensors are closest to the outside and the post-cats are towards the center. My Florida car had original sensors at 100K miles and it only took moderate force to loosen them.

7. The driver’s (US, left hand drive) side post-cat sensor is impossible to reach by hand from below, but is easily reached from the engine bay. I my case I loosened it from below with the wrench, and then unscrewed and replaced by hand from above. The three other sensors are easily reached by hand from below.

8. When unscrewing sensors, it helps to use your free arm to reach around the outside of the car and grab the free end of the wire in the engine bay. This will keep the wire from coiling around itself as you unscrew.

Hope this helps someone.

116klB

I broke the holding clamps on the factory air box! Are they available,2006 Carrera S?