Hi folks,
I completed a successful project on my 2001 Boxster haven't seen documented that I wanted to share: how to remove, clean, and lubricate the e-gas potentiometer. This may also be called a throttle position sensor. It has a fairly stiff spring in it that internally rub against its housing and this is what causes the "stiction."
The symptom of the service being needed is the accelerator pedal has 'stiction", or a "notchy" feel where it will not move as smoothly as expected. This may be worse at some times than others (in my case, it seemed temperature can have an effect). It can impede driving enjoyment and make smoothly launching the car using the clutch difficult, and is especially noticeable when crusing and making minor accelerator pedal adjustments (because you'll find the pedal won't quite adjust as you'd like).
You can first try disassembling and cleaning the accelerator pedal assembly, which is well-documented online. (For example, on these two renlist threads):
Edit: Exactly how should the gas pedal (BE REMOVED?!) feel? - Rennlist Discussion Forums
Sticky Accelerator on CPO 996 - Page 2 - Rennlist Discussion Forums
However, after tearing into the gas pedal, if you find there is stiction coming from the potentiometer above, this DIY is for you. The accelerator pedal connection to the e-gas potentiometer by a short length of cabling. If you pull on the cable end to actuate the e-gas potentiometer, and notice it making noise or not moving smoothly, service on the potentiometer is warranted.
The potentiometer is mounted to the brake pedal bracket by 3 10mm nuts and studs. Accessing them is bit of a contortionist exercise. The less limber mechanics may find it helpful to remove the drivers seat. (Otherwise, at least moving the seat all the way back.) Remove the heater duct going to the driver's side dash vent, and then you can access the three nuts from below, and reaching around from above if necessary. Use an open end and/or box-end 10mm wrench to get to these nuts. You'll want to have the accelerator pedal assembly either removed from the car, or connected to the cabling and "dangling loose". It is not necessary to remove the cabling from the e-gas potentiometer before removing it from the car.
It's not necessary to completely remove the 10mm nuts to remove the e-gas potentiometer. You can just loosen the nuts, and the e-gas potentiometer will slide out toward the back of the car, and can be removed from the car. (The photo shows the e-gas potentiometer, on mounting bracket, at lower right), and split apart accelerator pedal assembly and connecting cabling at left.