02 Sensor Wrench

[philbyil]

Howdy Folks...

Replacing my 02 sensor shortly and wondered if anyone has R&R'd one on a 525i M50 without dropping the exhaust??

If so, what type of socket/wrench did you use...

Thank y'all

[mzarifkar]

Ive done it before, complete pain in the ass, but i used the socket that has a cut out on the side to accommodate the wire. I did have to remove the heat shield between exhaust and driveshaft to be able to fit the tool in. make sure the car is redundantly secured if you raise it up. It took a lot of torque for mine to come loose.
my sympathies

[yaofeng]

I did a few times with a 22 mm open wrench without dropping anything. It is not bad.

[JD525IA]

Howdy Folks...

Replacing my 02 sensor shortly and wondered if anyone has R&R'd one on a 525i M50 without dropping the exhaust??

If so, what type of socket/wrench did you use...

Thank y'all

at least everything after the cat. The O2 sensor is on top of the cat. The socket has a slit in the side of it to keep from damaging the cable built into the sensor. Honestly, you could just cut the cable on the old one and use an open ended wrench to tighten the new one.

Dumbass me, I bought the socket for the 1st time I changed the sensor, then years later I couldn't find it and had to order another one. They are about $15 from Bavarian. Maybe you could get the free loaner from Checker auto parts.

If the sensor won't budge, use some PB Blaster to get the thread good and wet. There is anti-sieze compound on the new sensor's threads.

JD

[Jr ///M5]

Uncle Phil,

Drop the front of the exhaust, you'll need the room, you'll also need room to use a small torch to give it a little heat help. With the use of the open O2 wrench, you should be able to get it loose.

Rent a lift and it will be much easier.

Take care, give my regards to Deb, here's my new email....england31@comcast.net

Keep in touch my friend.

JR

[Ross]

I've never needed anything other than an open end or box wrench.
If the sensor is to be discarded cut the wire and use a (6pt) box wrench so there is less chance of round it off.
An open end is plenty for installation.

[bubba966]

I changed the O2 on a '95 525iT and had to drop the exhaust because I couldn't get it out. Loads of PB and letting it soak for hours still didn't let it budge with the exhaust in place. Dropped the exhaust (and damn is it heavy) so I could get better leverage on it and still had a bitch of a time getting it out.

I did use a O2 sensor socket. Don't recall why I didn't want to cut the wire and use a regular deep socket.

But yes, you can get at the sensor w/out dropping the exhaust. But if it's in there rather tight you might not be able to get it out w/out dropping the exhaust.

[philbyil]

New sensor, tools out, car on ramps and Hey! Its easy to reach! No probs, right? WRONG !!

Remove wiring routing cover, cut wires, PB Blaster soak, mow the yard.
Get 22mm box wrench, strain, sweat, curse! Go get 5lb hammer, tap away......no budge! Curse!!!! CURSE!

BUGGER! So...I surrender!!! I called my local indie, told him the story and they said bring it down at 3.00 today!!

I'm too old for this....

Well, 25mins and $41 later...all done. Car runs great....lesson learned !

I changed the O2 on a '95 525iT and had to drop the exhaust because I couldn't get it out. Loads of PB and letting it soak for hours still didn't let it budge with the exhaust in place. Dropped the exhaust (and damn is it heavy) so I could get better leverage on it and still had a bitch of a time getting it out.

I did use a O2 sensor socket. Don't recall why I didn't want to cut the wire and use a regular deep socket.

But yes, you can get at the sensor w/out dropping the exhaust. But if it's in there rather tight you might not be able to get it out w/out dropping the exhaust.

[Ross]

5# hammers aren't for tapping.

[Gene in NC]

How bout on '89 525, m20?