My wife's car check engine light came on about two month ago and dealership said she need a new cadilitic converter is there anyway to bypass the sensor? Havent addressed that yet. Also in the past few oil changes I've noticed an oil leak above the oil filter "any ideas" thought it was the main seal so I put a liquid seal restorer adative in with the oil. After about 3 weeks Now the car sounds like a weedeater when u accelerate gets louder the faster you go. While driving you can put the car in nutural and press gas to 4000rpm sounds doesnt change it depend on speed of the car I dont believe it coming from the motor maybe trans? Differential? And ideas?