Well my 90 was running relly rough. Changed the plugs, wires, cap, and fuel filter. Dumped a $2.00 bottle of STP injector cleaner in, no luck. Was getting ready to change the 02 sensor when I bought a $12.95 bottle of fuel injector cleaner. Runs like a new car. I'm probably still going to change the sensor, 161,000 miles, I've put about 40,000 of those on it and I know for the 30,000 before that it hadn't been done.

 

What brand $12.95 fuel injector did you use?

 

STP, said it was synthetic fuel injector cleaner, worked immediately.