1990 Toyota pickup 22re 4x4.
Has been doing this for years. But its sputters when ceuising at about 55 mph. If i push the gas down farther or let off it stops the sputtering. Go back to trying and cruise at 55 and it does it again (seems like there is a sweet spot in the pedal that causes it). Now it only does it in the summer months and never when it is cold outside. Maybe once a year it will throw a check engine light but it only pops up for a split second then goes off to not be seen for months. Any ideas? Maybe O2 sensore faulty or airflow issue?