VALVE AIR CONTROL, 81-82 FEDERAL/CANADA
Air Control Valve, 81-82 Federal/Canada
NOT California emissions
Large back-fire on deceleration and/or between shifts usually means this valve is “no good” especially on 79 & 80 RX7’s.
Also, if the car will not pass an emissions test, this is the culprit 90% of the time. If your O2 reading is less than .5% and HC and/or CO is high, this is your problem.