OK so I’ve got this project truck I’ve been working on for a while figured maybe with your general mechanic knowledge you could help me a little. It’s got this issue where it dies at red lights now I just replaced all the spark plugs and all the spark plug wires. It has a brand new water pump and brand new oil switch when I first got it it would overheat and at red lights the oil switch turned off, so that’s fixed now And I have no check engine lights however, it still dies on me whenever I pull up to a red light. My first instinct is telling me it’s an air issue of some sort, however, whenever I look at the O2 sensors on my scanner, the first two seem to be alternating voltage appropriately, the third in the sequence doesn’t however, from my understanding the third is the one located near the exhaust and since the truck definitely has an exhaust leak that sensor is less of a concern. I had ran a couple bottles of the royal purple through it last year and it didn’t die at lights for a good while. Started doing it again a few months ago so figured i would go ahead and do the plugs and wires. Just put another bottle of royal purple in the gas today. 

im wondering maybe if it could be related to trans as it doesn’t like to shift properly. I usually let the rpm sit around 1750 when I can hear it’s trying to change gears and just wait until it shifts for me. It has issues going from 1 to second and from 2nd to 3rd but gear 4-5 are good. It dies when I slow does to quick or when I am slowing down and turning which is scary cause the power steering dies. I don’t drive it regularly but trying to fix this issue so it’s not a death trap.