Hi, head scratcher here, (for me anyhow),vehicle arrived eml lit, po131 present, in live data bank one oxy sensor reading constant 400mv, adding fuel or creating air leaks did not alter this reading. Assumed oxy sensor failed so renewed with NTK unit, this new unit refused to operate at all flat lining at ov regardless of WOT or idle, or RPOT (rapid pumping of throttle!).
Aha, thought I as I discovered a split pipe to pcv valve, renewed this item, no better!
Also plugs in very bad condition, yet eml came on again after drive of about 10 miles, yet when monitored the oxy sensor is now behaving well between 130mv to 800mv.
Sorry about long post, will not object to long replies!
Thanks phil