p2196

Hi, Im new to this forum. P2196 code on my 2005 corolla CE. The scanner shows the precat (new Denso) sensor is sending about 3v to the ECM, too hight right? The post cat is ok about 0.5 v steady. Injectors, PCV valve, spark plugs, ignition coils and valve cover gasket have only 2500 miles on...