hey guys, need some advice, i have my as light lit and i have a computer report for it saying that the speed sensor in my rear right tire is out.
the thing is the mechanic says itll be about 300 to buy a new sensor and install.
Is this something i should really replace asap or what could i do about it?

also there seams to be a heavy almost deep breathing sound coming out of the front end of my car, i have a stillen intake but I almost want to say its an exhaust issue, car is running just fine, it just makes that sound when i startup and turn the car off, it may be running alittle louder too. any advice?

thanks!!