I have a 97 Del Sol automatic (d16y8) with 1320 headers & a cold air intake & cat delete. 150,000 miles. Hard bucking / stuttering when accelerating at low speeds - less intense but still obvious when I give her more throttle. Even at cruising speeds with slight throttle, the RPM’s jump up 500 or so, and the torque converter partially disengages until I give her heavy throttle. Horrible fuel trims on bank 1. Loud humming noise coming from the end of my CAI filter at times when it’s worse.

The weird thing is - whenever it’s hot out (>75) and I drive her for over an hour and get her pretty warm, she runs PERFECT.

I’ve ruled out a vacuum leak, new fuel filter, new CAI filter, TPS sensor, cleaned intake & throttle body, and just put in a new o2 sensor in - did not help. Transmission is fine as well. I started data logging to see if anything else was acting up - files attached

2 mechanics who just “don’t have the time to try and figure it out”

Only cell I get every few weeks is P0441 “EVAP incorrect purge flow”

Is the erratic o2 voltage in the data logs the cause or a symptom?

The first car I’ve bought & loved myself. PLEASE HELP