DIY - Replace O2 sensor for 2001 330i
 

I have seen a DIY referenced but cannot find it. I think I'll need to buy 2 O2 sensors and replace them but don't want the dealer to charge me $700. Thanks in advance for the link!

Re: DIY - Replace O2 sensor for 2001 330i
 

Don't every one reply at once...is this so difficult that NOONE has ever done it before?SmileWavy

I think you have 4 O2 sensors. You should get check engine codes telling you which one is bad. I've heard 2 are hard and 2 are not so hard. I think you need a specialty socket to fit over the O2 wire. Ive never done it nor do I know anyone that has on an E46. Yet...

Hey, thanks for the post. I have seen where there is a special socket with a slit or something in it. I just don't know where they are located. I have read that the pre-cat ones are not as hard as the post-cat ones.

Anyone have a picture of where they are located? I think I can figure out how to remove them...I'll also take photos and do a DIY for everyone.

Your socket description sounds correct.

I dont know if pre or post cat is harder.

The cats are close to the engine, probably just where the pipes reach the bottom of the car. They should be easy to find and they should have some sort of heat shield on the bottom of them. They look like little mufflers.

Are you certain you need O2 sensors?

Actually not yet I don't. I know I'm at 100,000 miles and the Check Engine light just came on. I thought I'd do the research before, just in case. I'm going to buy a code reader I guess to check the code. With the E46 you gotta have the reader right?

Yes, you need a code reader. You local BMWCCA might have one to borrow.

You can get a Peake or a generic OBD-II reader device or a generic OBD-II reader attachment that works with a PDA or laptop.

A CEL could be anything. The most common cause is a loose gas cap. Usually when you let a loved one borrow the car and they buy gas.

I've seen the gas cap mentioned before, and haven't checked it yet. I will do that now just to be sure.

I'll do a check for the BMWCCA here in Huntsville, Alabama. Not sure if we have that association or not. Thanks for the help!

If it was the gas cap, simply putting it on right wont instantly make the light go out. It goes out after a short while.

You really need to have the CEL codes read before we specualte about what problem you have?

OK thanks Jeron. I will get the reader then post after I see the codes.

Thanks!