a quick question bout the o2 sensor and exhaust
 

hey guys.....i am planning to upgrade my exhaust from headers on back.

i have a magnaflow cat and want to get a remus from bavauto.....

basically i just want to do a simple remove and replace both parts all in one piece. i am considering replacing the o2 sensors as well. so one, i want to know when should i replace them? i have about 94k miles and as far as i know they have never been replaced. also i noticed that bavauto sell an o2 removal tool. is this really needed? i just wanna make sure this is a pain free as possible.

my car is a 97 so i have two o2 sensors.

thankz for the help

I don't consider 02 sensors a maintenance item.
Meaning, I replace them when I get constant CELs.
But since you have everything down, it might not be a bad idea.

An 02 tool will make it easier. I'd get it.

The tool is not absolutely necessary, especially if you have the entire exhaust off of the car. You can easily fit an open or box end wrench on them and break them loose. After a few turns with a wrench, you'll probably be able to turn them by hand. Just make sure to unplug them first so the wires don't get all twisted up.

thankz.....do u know what size wrench would work?

I bought one of those o2 sensor sockets from advance auto for $4. I think it is 22mm.

Are you planning on replacing the headers? Or just the cat and catback?

If you considered the Supersprint system it's on sale at HMS for half price. Remus unit is very nice as well. If you replace the factory manifolds aren't you going to have issues with state inspection?

My M3 would not pass under the previous owner when it lived in Indian Head Md. it just needed a ecu chip swap back to stock.

Not that a header is going to pollute anymore they just frown on them because of visually they are not stock.

OBD-II they only look to see if you have a cat and no faults.

Depends on the state, Mass is no requiring you to have Stock exhausts. I was cited last year and I am not even registered in the state. They do look in some places.

Probably, but the OP is in Maryland. They only care that there is no CEL and you have a cat.

no headers, i thought about it but they didnt need to be replaced. cat and cat back do, so i figure its a good time to just do an upgrade.

i saw the sale on the supersprints.........i thought about it but didnt know if it was direct bolt on and from what i remember in the exhaust discussion, SS were louder than Remus. and i just want more free flow with a nice deep throaty sound.......nothing too much louder than stock.

am i correct though, i dont wanna miss out on a great deal becuz i was wrong...