I’m getting P0352 on my ’08 Toyota Sienna. Even after the dash lights up, the vehicle runs perfectly smoothly with no indication of ongoing failure (e.g., idle smooth, acceleration normal).

If I clear the code everything will be fine, usually until I start the vehicle and then the code comes in after a few minutes of driving. Once it came in while idling at a stop light, and I did feel the engine miss I’m guessing a single fire, and the dash lit up right after.

Does this sound like a failing coil or an electrical connection? Of course I can replace the coil, but if it’s an electrical connection somewhere upstream, then coil replacement didn’t do me a whole lot of good.