I had a problem. It just plain stopped working. When I first put it in it ran great. Then one day I pulled in the driveway, shut the car off, and that's all she wrote. No more spark. Their techline was very helpful. SAVE YOUR RECEIPT! It was 10 month into 12 month warranty so they replaced it. I have yet to put the new one in. Conversely, I have heard much more positive than negative feedback regarding Pertronix.