car lost power

[eighth]

The last time I dynoed my car a year ago it made 321 and i just dynoed today on the same dyno and i lost 40 hp but my check engine light was on cause of a bad o2 sensor could that be the cause of my power loss and sugestion is welcomed.

 

[Hitmachine101]

yes that is the cause of some or all of the lost power,, change your o2 and you should be back to your mark of last years dyno -- keep in mind that with a bad o2 your computer is going to make your car run super rich -- think its about 20% more fuel then normal

had a friend who ruined his evo because he was to cheap to pick up an o2 -- he washed the cylinder walls down hard core

hope this helps