Spent $140 on a "premium" O2 sensor kit and a week of my life before a $12 part fixed it
My truck threw a P0135 code back in March so I did what any reasonable person does and ordered the fanciest downstream sensor kit I could find online, $140 shipped, plus a special socket I needed for the job. Two weekends later, after pulling the old sensor, cleaning the bung, threading in the new one, and clearing the code about seven times, the light came back on the drive to work on a Tuesday morning. I cussed in my driveway at 6am loud enough that my neighbor's porch light flipped on. Took it to a shop run by a guy named Manny off Del Paso in Sacramento, and he poked around for ten minutes before showing me a chafed wire about four inches up the harness, rubbed raw against a bracket. He soldered it, wrapped it, charged me $12 in parts and didn't even bill the labor because he said he felt bad watching me pace. The fancy sensor is still in there working fine, so I guess I bought a spare for the future. Point is, I chased the code instead of chasing the wire, and that is the rookie move that keeps this community in business. What is the cheapest dumb thing that turned out to be the real fix for you?