Chuck & Peter, I need your help again. Just had neutral safety switch replaced because car, 87 300e, had died. Tested for CO adjustments- got 90.5 fixed with key on, engine off. Disconnected O2 sensor & attached to a new one in the box. Same reading. With engine on, fluctuations on meter only between 90.1 & 90.8 & no meter changes as I adjusted the screw & the engine got lower in sound & smoother. Wires appeared connected in tester. Now what?
Thanks
Rich