Spark knock then maybe?? Given the mileage, wonder if the timing chain has stretched beyond usability.... The large leak needs to be addressed as well.... Check ALL the hoses for the EVAP system.

 

Neglected how? Any low oil episodes, or overheats? Those are the real killers.

 

just not driven it sat in my dads yard for a while

 

My uncle just ran his scanner on it said large and substantial evap leak so he’s getting the diagram for my lines and is gonna go through them there’s also a bad o2 sensor on my driver manifold I have Cali emissions on it so there’s 4 o2 sensors…yippee

 

The rubber lines usually crack at the ends but it's good to also squeeze the hoses along their entire length for cracks. You can cut off the cracked ends and reattach if you have enough length. There are usually lines underneath leading up to the Evap canister too, at least they are there on my 4.7 quad cab.

 

If you have one bad O2 sensor, replace them in pairs. (fronts, vs. rears) They all live in the same environment, and have a variety of failure modes.....

 

yeah we only replaced one out of 4 of them and the other downstream one went bad (Cali emissions) so I’m just gonna replace the rest of them and then go through my evap lines, but would this result in the issues I am having?