Quote Originally Posted by AveoJoe View Post
I had an Opel gt 1979 or SOMETHING? Yes the check engine light is on I added an o2 sensor extension just the other day but light went back on. Let me see at a tank full 10 gallons the car gets 365 miles so thats 36 mpg and the engine is steady. I only use BP gas from day one. ngk plugs and wires. Car runs great. My bad I did take off the o2 one time and yes it did affect the ecu so back it went.
probably the water in the gasoline.
XD Couldn't resist.