I have a 97 s10 with automatic trans that won't down shift to 1st or shift in to 4th. It stays in 2nd and 3rd gear while driving and will go into reverse to back up. I know way more about engines than transmissions. Will it be the 1,2 - 2,3 sensor causing my problem? From what I've read online, this is more than likely the problem. Just wanting a second opinion before throwing money into it.

 

4L60 E (an electronic shifting 700R) had a lot of problems, your was/is one of them. I got mine rebuilt to 4L70 E, more clutches and some other parts, it's the tranny than comes in the SS models. I would recommend you find the best shop in town and have them do the work, you could remove the tranny yourself and reinstall it to save some money but I wouldn't, they should offer a warranty (and if they don't you don't want to spend your money there) and if you have a warranty claim THEY get to take it back out. They are most likely way better set up to remove a transmission than most guys are at home.