check engine light /code P1123 on '99 Carrera
 

I had 2 O2 sensors replaced Friday out of state and ck eng light came on again within 24 hours. I had Autozone use a scan tool and they read a code P1123 which we looked up and for the '99 911 and says " Thrttle position sensor is within range but higher than nornal. Does anyone have any experience with this? I am mechanically able and have an ohm meter and other tools, just don't want to take to dealer if possible. The car is all stock and has 34k miles, runs great, 25.1 mpg ave on 1800 mile trip earlier this week.

The scan tool does not mean anything unless you check the exact way of testing that fault code. For less than the cost of replacing the sensors the dealer can run the system on the Porsche PS2 system tester. Don't even bother with scan tools, as they tell you only the number.

I have a 99 purchased in June. The CE lite came. First repair-reset lite, added fuel additive. Lasted about 24 hours. Second repair at dealer-replaced mass air distributor for $500. Lasted 24 hours-next repair at dealer-replaced Oil separator for $900. THis fixed the problem.

I think you need the computer to run a deep test to determine the problem. You will not find it by yourself.

maybe I got lucky. I had the Autozone guy turn off the CE light and went home and removed the air box, filter, and rubber boot connecting the throttle body to the box. One clamp down stream from the MAF sensor looked a little askew so when reassembling I made certain the clamps were tightened moderately and perfectly centered. I also disconnected and reconnected the TP sensor a couple of times to assure a clean connection. It's been a couple of days now and no CE light.

So, is the light still out? P1123 is O2 sensor adaptation at lean threshold cyls 1-3. P1125 is cyls 4-6. The sensors are sensing a lean mixture, which means the sensors were working, and did not need to be replaced.

I have the same problem and my car fail smog test.
here's what i had done so far with no luck.
1. replaced all 4 new O2 sensor.
2. clean throttle body
3. clean mass air flow sensor
4. Reset code
5. perform drive cycle

P1123 is still back on.

Any idea?