Dang dude, much obliged; can't tell how many people get help and solve problems without telling us what fixed the issue. Very cool man.:welcome::hail2:
More info, mods or tunes? If you do have a vacuum leak, local mechanic should be able to run smoke through vacuum system. On the upside engines produce water from the air so when it is cold on start there is some H20 in the system.
Malfunction of oxygen sensor bank 1 number 2 and a misfire of cylinder number 4; Google to double check. Seems like it is time for a tune up such as sparkplugs and coils. 1000 for an intake? If that is the case; do it your self and get a Ford Racing lower intake and gaskets.
I wouldn't sweat it until it becomes a problem, use the highest octane of gas and from a trusty fuel pump to isolate fuel being an issue. Cars change moods like people when the environment changes.
So what you are saying there is no need to tune for meth on a mostly stock car, I'm also considering meth for cooling properties. Keep us posted about your meth setup, Sneaky. Meth is a world not delved in often.
My guess is throwout bearing, get a new pilot bearing and do a fresh clutch job with rear main seal if cash flow permits. Are gonna drop the transmission. Resurface flywheel.