97_SI

i have an Is250 and my exhaust is leaking. So i am thinking about replacing the entire exhaust system with an aftermarket one. My question is, will it make any the engine light or any other dashboard light go off? I would hate to see Engine light go off on me. Thanks

White Devil

Depends on what you replace. If I remember correctly, the IS250 runs an O2 sensor with the cat. Since its OBDII, if the O2 sensor is removed it will throw a CEL if another one is not added in.

When most people talk about "replacing the entire exhaust system", they mean from the manifold to the tailpipe. What do you want to replace?

97_SI

Delbanner thanks for the reply, here is what i am thinking of getting
http://thmotorsports.com/i-128996.as...ingSeanVehSpec

So i am guessing this is not from the manifold. Will the O2 sensor stay the same?

White Devil

Alright.... Ill help you again.

An exhaust system comes off of the engine block headers into a manifold that joins the header pipes together (3 on each side for a 6-cylinder, 4 for a V8), then the manifold runs the exhaust towards the back, passing through a catalytic converter (or 2 cats, depending on the setup). Depending on a cars setup, there can be an O2 sensor on a downpipe from the manifold (as commonly found in turboed cars), one directly on the manifold itself, right before (or even on) the cat, or maybe even one near the muffler in some performance setups. The setup youre showing is called a "catback" exhaust system, meaning that everything behind the cat is getting replaced. And since this setup shows no O2 bungs on the muffler, that means you won't lose any sensors if you use it.

What you SHOULD do is before you buy anything, get the car on a lift and look underneath for any wiring coming from these different areas of the exhaust. If there are no wires or obvious sensors poking out of the muffler area after the cat, then youre good to go.