should I pay $1000 for new knock sensor

[Rave for Rav]

My engine light is on and I took it to Toyota for diagonostics. The car is running very badly. No power. The gas milage went from 27mpg to 15. Our own auto mechanic says that we must replace the knock sensor or we will not get our performance back. He says it is controlled by a computer chip that limits the amount of gas avaiable to the engine in order to protect the engine from overloading.

Please help because my husband and I are in a battle. I think the engine needs the fuel injectors cleaned and generally needs a tune up. My husband says that will make no difference until we get the kncok sensor replaced.

It will cost $1000 to replace the sensor because our Rav is 4 wheel drive.

Help us please

[Yota_Fiend]

WOW. just, WOW. I hate to tell you, but that mechanic is screwing you. if thats really what he told you, that doesn't make any sense, and he shouldnt be trusted.

I cant really help you with a driveability problem without being there and testing it myself, so i HIGHLY recommend taking it to another well know shop. working for toyota, i hate to turn people away from the dealer like that, but im not going to let some guy like that screw over a customer like that. it isnt right.

yeah, it could be the knock sensor. but it doesnt cost 1k to replace. the sensor itself is not anymore than 100$, and thats worst case scenario.

the knock sensor has NOTHING to do with your 4wd, or anything driveline related. dont let him tell you otherwise.

and as for the tune-up, i dont recommend doing that just yet. You need to figure out the problem before you start trying to fix things. you shouldnt pay for stuff you dont need. Not to mention that theres really no such thing as a tune-up anymore, believe it or not. your not paying for anything but for us to take out your spark plugs and look at them, then just look for anything broken. thats it.

[Rave for Rav]

Thank you Yota Fiend. I guess I should clarify. Both the dealer and our neighborhood mechanic said that replacing the sensor would cost $1000 because they would have to pull the engine AND transmission to get to it. But if the sensor is not causing the performance problem I don't want to spend the money just to replace a sensor...I can live with the check engine light on.

[typesix]

Don't know which engine you have but on the 2.4l 4cyl, the intake manifold needs to be removed in order to replace the knock sensor. The sensor doesn't limit the amount of gasoline, but reduces the sparkplug timing to prevent pinging. Reducing the timing will reduce the power and fuel efficiency. Yes, go see another mechanic for diagnosis.