So the Infiniti was shifting a bit rough, sticking in gear, and so on. Thought maybe the transmission was on its way out. (At 15 years and 254k miles, it’s lived a hearty life)

Threw a P0720 code, for Output Speed Sensor Circuit. So, I went to AutoZone, where they charged me $125 for the part.

Just kidding. I balked at the price, and promptly ordered the same part online for $50, including shipping. It came last night, and got put on today. After jacking up the car, and removing the front driver’s side wheel, the old sensor gets removed, and the new one gets put on. Doesn’t take too long. Clear the code, take it for a test drive, and it seems a whole lot better now! Instead of revving to 4000 rpm and not shifting, or shifting extremely hard, it now shifts between 2,000-3,000 rpm, much more smoothly, and acceleration isn’t as throaty as it was. Funny how such a small piece with a plug on one end and green gears on the other could cause such frustration.

Next step, find out who the fuck dinged my back door, when, and how, and make them pay.