Nissan Micra K11 2001 CG10DE 16v (Bosch 4.6) - MIL on P0131 O2 lean #Archived Message
Posted by stuartwright on March 25, 2007, 9:53 pm
M.I.L. present = P0131 O2 sensor LEAN; output hovers @ 50-70mv & rarely goes over 500mv; Live data initially shows B1#1 O2 sensor output @ minus 48v!, post cat sensor indicates 600 to 700mv & is 'switching' ECU cntrl. However, when Eng coolant temp is selected the value appears normal BUT this value is then represented in the B1#1 sensor window and the value tracks coolant temp variations ! I've got to return to the car Monday to check values @ ECU..... A previous post suggested a coolant temp harness mod! Does anyone have any info on this mod? (Interrogated with TEXA Ax2k) Done more testing...I've tried 2 new O2 sensors with the same results (before setting this post)...same voltages @ ECU pins, however when hot the B1#2 sensor is logging a consistent 260mv output(LEAN) There are no exhaust leaks around Ex manifold or sensor. There is no EGR on this model and I'm now getting suspicious that I may have a MAF problem despite no code reported. I've interrogated the system both thro' KL mode (Where I get the peculiar -48v) and directly into EOBD where I get 0 to 50mv. Removing Vac' line from fuel press reg (& plugging to increase fuel pressure) makes no difference. (fuel pressure is OK)