i drive my car every day 100 plus miles and its fine. when i put a load on it though the check engine light starts flashing 10 seconds on 10 off(1 blink)the it flashes twice and then off then it flashes 3 times then off. i went to checker-oriley and they said 2 thing 1 its my motor missing while going up hill(full throttle) or down hill (no throttle) and that they had a obd1 &2 tester so i hooked it up and it said 3 codes low oxygen, high oxygen, map sensor fault so i fixed the vacumme leak cleared codes and then the 2 oxygen sensor comes up again. so i change the oxygen sensors and the check engine light still does the same thing. so im baffled at what my car is trying to tell me, anyone know.