AudiForums.com - Engine codes p1113 & p1131

The ecu checkes the currect draw of the heater grind in the O2's, that is how the OBDII system know the O2 areheating up so it can go into closed loop.the heater grind is problably bad(when I went to BOSCH school there were using platinum platedon the ceramic, the platinum after time will get a fracturein it and like a stove element not work any more. hope this help, I see this is not the place for this but though I would reply to the question. both O2 will most likly need to be replaced.

info on O2's
Oxygen Sensor Control, Checking

Function Of Oxygen Sensor Control
The oxygen sensors compare the oxygen content in the air with the residual oxygen content in the exhaust gas and send a voltage signal to the control module.

The voltage signal for "Mixture too rich" (low residual oxygen) is between about 0.5 and 1.0 V (relative to reference Ground (GND)).

The voltage signal for "Mixture too lean" (high residual oxygen) is between about 0 and 0.5 V (relative to reference Ground (GND)).

The transition from "rich" to "lean" is accompanied by a voltage jump from between 0.5 and 1.0 V to between 0 and 0.5 V (relative to reference Ground (GND)), and vice versa (Lambda = 1.0 ).

Because of the sharp voltage jump the oxygen sensor control cannot maintain a constant ideal mixture composition of Lambda = 1.0. The system fluctuates continuously between "slightly too lean" and "slightly too rich".

If the voltage does not change or only changes slowly the following malfunctions are possible:

[*]Slits or holes in probe head are blocked.[*]Oxygen sensor has been subjected to excessive thermal stress.[*]Contact resistance in signal wire or Ground (GND) wire.[*]Oxygen sensor too cold; sensor heater not working.[*]Oxygen sensor damaged by contact spray or similar product. (The contact spray is drawn through the fine cavities in the electrical wiring as a result of thermal fluctuations and capillary effect.)[*]Oxygen sensor damaged by silicone vapors. (The engine draws in traces of any silicone-based sealants that may have been used. The silicone does not burn and damages the oxygen sensor.)[/ul]