
Is that wire from the downstream o2? That would definitely cause poor performance, I believe if the ECU can't see both o2 sensors it defaults to full rich mixture but I could be wrong. You said you have a CEL? What code(s) is it showing? What dizzy are you using? Checked plugs? What gas are you running? I would definitely look for a VE ecu, it can only help. I found a JWT tuned ECU right before I did my swap. I couldn't imagine running on the 259cc profile.