I replaced the CO2 sensor and relay in my MK1 1.7...car ran great for a few days after. No vibration, no loss of power, no weak launches into 1st gear. Car has new plugs, injectors, o-rings, etc.
Yesterday, I started the car, and the engine ran sluggishly, producing a foul-smelling exhaust. I re-started the engine, and it again chugged at a low idle.
I turned up the idle screw, and the engine came back to normal....now with more vibration.
Is this more than just a matter of the idle screw needed adjustment? I have a feeling I have a bigger problem, but I doubt it since I have so many new vacuum lines and fuel line components.