MrOverCast
OBS Enthusiast
Hi guys!
So I did the 0411 swap on my 98 L31 Vortec a couple months back and recently I started the engine for the first time. The engine ran like absolute trash at idle, Would barely even start. While monitoring data with torque pro I come to find out my O2 sensors are flat-lined.....450mv (NO CATS) even at full operating temperature. PCM logger says its in closed loop if that helps. I understand the differences in isolated ground O2's and Case ground. I believe my harness is for isolated ground. (flat black 4 pin connector). Someone said the o2 sensors get their grounds from the pcm and that I would have to move some wires to a spot that provides a ground on there. Does anybody know how to fix this issue? im really stuck here
So I did the 0411 swap on my 98 L31 Vortec a couple months back and recently I started the engine for the first time. The engine ran like absolute trash at idle, Would barely even start. While monitoring data with torque pro I come to find out my O2 sensors are flat-lined.....450mv (NO CATS) even at full operating temperature. PCM logger says its in closed loop if that helps. I understand the differences in isolated ground O2's and Case ground. I believe my harness is for isolated ground. (flat black 4 pin connector). Someone said the o2 sensors get their grounds from the pcm and that I would have to move some wires to a spot that provides a ground on there. Does anybody know how to fix this issue? im really stuck here