Low BLMs at idle and cruise

How in the world can a spark plug change affect how rich or lean your running by that much? I'm baffled by that resolve.
 
if 2 spark plugs are bad they wont be burning the fuel the way they are suppouse too, therefore the oxygen sensor will pick up extra rich on its end and send a signal to the ECU to take off some fuel resulting in low BLM's..
 
Do you still have the PCV system installed? When I blocked mine to gain manifold vacuum and gas mileage, my BLM's dropped about 10 points.
 
Originally posted by wiked87gn
if 2 spark plugs are bad they wont be burning the fuel the way they are suppouse too, therefore the oxygen sensor will pick up extra rich on its end and send a signal to the ECU to take off some fuel resulting in low BLM's..

Now I can see that, but I would also expect the car to run like crap if it had two bad spark plugs.

Ross said: "On a side note, the car seems to be running fine, and it is hauling ass. 21psi, no knock..o2's in the low 800's."
 
not necesarily, it could be that at idle the spark is so low that is messing up burning the fuel but at WOT it increases thus creating a better burn and no bad BLM's..
 
Originally posted by wiked87gn
not necesarily, it could be that at idle the spark is so low that is messing up burning the fuel but at WOT it increases thus creating a better burn and no bad BLM's..

This might be the case.

It seemed to run pretty good before at WOT.

The idle now is smoother than it was before the spark plug change. It also is running smoother at cruise.

The car is running great all around now.

To those of you with doubts, the spark plugs were the only change I made, and it corrected the problem.
 
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