You don't say which model your car is, but I'm assuming it is a 986, and DME7.2 (or 7.3 perhaps). It is the pre-cat sensor on bank 2 that seems to be on the way out, or there is an air leak, or the wiring is faulty. The most likely culprit is the O2 sensor itself - a very common failure. (TWC = Three Way Catalyser, or catalytic converter to you and me).
P1275 16 Signal Delay Time for Oxygen Sensor Ageing, Bank 1 – Above/Below Limit
P1276 22 Signal Delay Time for Oxygen Sensor Ageing, Bank 2 – Above/Below Limit
Function
The diagnosis of "oxygen sensor ageing” helps to identify oxygen sensors ahead of TWC that lead to emission limits being exceeded because of ageing.
The value of the higher-level I-controller is used to detect a shift in the sensor characteristic. Within the framework of the 2-sensor oxygen sensing system, this I-controller ensures that a level of emissions which conforms with regulations can also be achieved for a sensor with a characteristic shift via the delay time of the oxygen sensing system.
Diagnosis conditions
– No secondary air
– No diagnosis of secondary air system
– No fuel tank ventilation
– Oxygen sensing after catalytic converter is active
– No faults for misfire detection, throttle valve, oxygen sensor heating, camshaft position sensor, fuel tank ventilation system, EVAP canister purge valve output stage, voltage supply or mixture adaptation.
Fault conditions
Fault threshold exceeded.
Fault area
– Oxygen sensor ahead of TWC
– Leak ahead of TWC or in the area of the oxygen sensor after TWC
– Wiring (oxygen sensors exchanged)
