I'm having an issue with my 05 Buick allure cxs. Purchased knock sensors, both have same size threads, only problem is my car has 2 different thread sizes? The front one is standard size but the rear takes a smaller bolt/end/thread. I found one with smaller threads but it keeps kicking out a code saying low voltage to that sensor? I've triple checked the wiring for bad connections, replaced knock sensor twice, replaced and reprogrammed a new Body Control Module. Still have low voltage issue. I've been dealing with this for months and getting no where. I'm down to thinking maybe the back knock sensor with smaller bolt insert is the problem. Not giving off correct signal? Help!!