2005 Mazda Tribute, 3.0. I was driving home the other night and it just died on me. I managed to limp home. Its throwing a po352 and po354 code. That is a coil on plug circuit failure. I have easy access to the front 3 plugs and coils. I switched the coil to cylinder 5 and the problem does not follow. From what I can tell the coil is fine. I also changed the plug on coil 4 and made no difference. Unplugging the coils with engine running, I get a power drop on coil 5 and 6 but nothing at all on 4. I tested 4 for spark and have non, I have spark on 5 and 6 no issue. I assume on the back harder to reach side, the issue with # 2 will be the same as #4. I assume I have no spark on 2 as well. I also assume the coil is fine on 2 because the # 4 coil is fine when switched to other spots. So I have a code for misfire on 4 and 2 and confirmed no spark on 4, and also confirmed moving coil to 5, with no problem. I traced as many wires as I could and cannot find any shorts. with the key in the power position, I have 12 volts at all coil connectors, in the front anyway, I have not removed intake to explore back side yet. What else can I try, why no spark at #4. I am hoping the PCM is not shot. Could a cam sensor be at fault? thoughts?