O2 Sensor Bung Cross Threaded. Now What?

~JM~

Wrinkled Member
Joined
Oct 31, 2007
Look at this happy surprise I found today.

The new sensor didn't stand a chance of threading in correctly.

I think I know where this is headed, but I hope there is an alternative option. Whatta ya'll think?


O2.jpg
 

Pronto

You can't knock them up with spit.
Joined
Dec 9, 2002
The bung is probably ss. Maybe you can chase the threads with a sparkplug chaser and save them.
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
Buick sure placed it in one hell of a location.

Suspect the manifold/header will need to be removed. Really don't want to do that if it can be avoided at this time.
 

Pronto

You can't knock them up with spit.
Joined
Dec 9, 2002
Oh, it's the stock location. That is tight in there. Shop around for a chaser. There may be a shorty one that will fit.
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
So, I've received a couple of recommendations on using an O2 sensor thread chaser or a tap.

What size is required & how does one proceed in the stock O2 sensor location?

I'm concerned about the angle of attack, limited access/visibility & chips being blown through the turbo. If the tap is well greased will it capture the chips?
 

TurboTGuy

Gray Beard Member
Joined
Sep 24, 2010
Looks as if there are several methods to solve your issue out there.

Still most likely gonna be a booger. Best of luck!

Let us know how it goes.
 

Jerryl

Tall Chinese Guy
Joined
Dec 14, 2004
Chase it, never seize it, send it. Lol

Don't worry about the chips. Once the engine is started, they will blow right past the turbo.
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
Attempted to chase the threads & repair the damage. I think it may have been done before as the entrance to the threads were not square or straight. It cleaned up enough to allow me to install a new O2 sensor, but it doesn't seat square with the casting shoulder. I'm not satisfied with the repair & will have to remedy the situation eventually.

Anyone know why the sensor is located on the backside like that?
 

TexasT

Texas, Where are you from
Joined
Sep 10, 2002
Not a real big deal to pull that header and have the old bung removed and a new one welded in. But it is work. I'd send it like it is and see if I could hear/feel it leak. Watch the boost to see if it is steady.
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
Not a real big deal to pull that header and have the old bung removed and a new one welded in....

But I'm one of those "While I'm at it..." kind of guys. There is no such thing as an easy, or simple, job.

I still have a lot to do & have it up & running before October arrives.
 

John Larkin

Sublime Master of Turbology
Joined
May 25, 2001
I put one of these on my downpipe for the wide band: O2 Ring Flanged

They are $30 but super nice and easy for someone to weld, nice wide flange. Take it to a good welder and they can knock it out in a day. There is an option for 3" pipe or 2" pipe. The header main tube may be 2", not sure.
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
I have an O2 bung on the downpipe that I just installed. I figured that may provide some options. Not sure what they are yet though.

DP2.jpg
 
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