Chrome hero, you are my hero. I had an issue with my daughters 05 neon. p0720, p1790 and p0731. I had replaced both speed sensors but the issue would not go away. Your post saved me a ton of time!! I found a broken wire right at the output speed sensor. same situation. the wire was broken inside, was not visible. fortunately I am a mechanic and have found many wires broken inside their casing. It was also right at the connector, and it was at 7 pm last night, so new end was not going to happen. I pulled connector apart and soldered wire. reassembled and problem solved. Thank you for taking the time and writing this long detailed post, I greatly appreciate it!!
