P1276 on 2000 Boxster

[stateofidleness]

Hi all - getting my Boxster back on the road. Has been garaged on trickle charger for about 8 months. I've driven it the past couple of days with no issues, but today, I got a solid CEL (P1276 when I used my code reader). Below are the "live" values I was able to capture from the code reader. From what I read this points to 02 sensor. I have cat bypass pipes and aftermarket muffler on my boxster, but I have the stock headers (and don't remember ever messing with 02 sensors during the swap). To be honest, I dont know if this means I have 2 02 sensors or 4 on the stock headers. There's no 02 bungs or sensors on the cat pipes or muffler.

 

Can yall tell me what best plan of attack is here? 2000MY non-S with roughly 95k miles and no other issues present.

 

Param	Value
Bank1 Sens1	02S Outp 0.100V
Bank1 Sens1	STFT 6.2%
Bank1 Sens2	02S Outp 0.110V
Bank1 Sens2	STFT 99.0%
Bank2 Sens1	02S Outp 0.600V
Bank2 Sens1	STFT 2.3%
Bank2 Sens2	02S Outp 0.710V
Bank2 Sens2	STFT 99.0%
Engine RPM	828
Fuel System 1	Closed loop
Fuel System 2	Closed loop
Load Value:	3.50%
LTFT Bank1	-13.20%
LTFT Bank1	-11.70%
STFT Bank1	5.40%
STFT Bank2	6.20%

Edited November 14 by stateofidleness

[Loren]

P1276 Signal Delay Time for Oxygen Sensor Ageing, Bank 2 – Above/Below Limit

Possible causes:

– Oxygen sensor ahead of TWC
– Leak ahead of TWC or in the area of the oxygen sensor after TWC
– Wiring (oxygen sensors exchanged)