My van has been sputtering it will not accelerate but only when engine is cold once it warms up after about 5 minutes of driving it drives just fine… I have replaced spark plugs, wires and the coil pack… I habe also replaced both o2 sensors (thats what my check engine light is on for) and none of these have fixed my problem… I also went from getting 28 miles per gallon to now only getting 11.8… I have had my mechanic run a severe diagnostic on my vehicle and the only thing that comes up is high circuit O2 sensor. Please someone help me out
We need the actual codes in the form of P9999 to be able to assist
Have the mechanic check if the coolant temp sensor for the computer is working properly.
If the computer thinks the engine is at -10 º, the engine will run rough and get lousy mileage.