Check Engine light went on, pulled a 1-3-1- code = fuel injectors. Checked voltage to each, unplugged one at a time and started the car. There was a difference in the idle each time an injector was pulled, so they are "buzzing".

Gas mileage is terrible. The old exhaust system is rusted and will be replaced from the exhaust manifold back, along with an oxygen sensor. There is an exhaust leak that you can feel under the head pipe. I unplugged the oxygen sensor, started the car and there is no difference in idle.

My hunch is that the oxygen sensor is attempting to compensate for the exhaust leak by dumping more fuel into the mix, but the injectors can't keep up. (?)

Any other thoughts? I did clean the throttle body (TPS is good)and the AMM is good also.

Thank you,

Stormie