How should I cut my o2 sensor bungs? LT headers

[Quickster]

I needed my o2 sensor bungs to be on the outside of my long tube headers, so I bought some bungs to have welded on. When I dropped them off to be welded on it slipped my mind I needed them to be cut down cause they were a tad too long.

Outside shot, original bung on the LEFT, new welded on one for the RIGHT.

Inside shot, I put a o2 sensor into both to give you a look. Again Original bung with o2 sensor in, LEFT. Then new o2 sensor bung with o2 sensor in, RIGHT.

I need the o2 sensor in the new welded bung to be more in direct stream of exhaust gasses.

The bung is about 6 1/2" deep from the end of the collector. Not sure if I want to attempt to cut it down from INSIDE the headers, or take a cut off wheel to the outside of the bung and try and cut it nice and straight. I don't have a tap or anything that large to clean up the threads though.

Threads are M18

 

[theknurl]

the threads are M18 x 1.5.....

its better to put the 02 sensor as close to the exhaust valve as possible

is the motor injected or have carburetor?

 

[Quickster]

Injected
LSx motor

 

[rsanter]

I would reach a cut saw blade up in there and then clean that up with a die grinder

Bob

 

[APEowner]

I can't tell from the pics if it's too far from the end of the pipe for this to work but it it's close enough I'd stick a die grinder down in there and grid off the excess from the inside.

 

[jsaw]

Reach in with an extended length die grinder and long bit

 

[bullnerd]

Sawzall.

 

[Quickster]

I attempted to use my sawzall but I only have some 6" blades on hand.
Will have to pickup some 9" ones or longer.

Also the blades are too tall, from the teeth to the top of the blade. So if I can't find some skinnier ones I guess I will have to cut down the blade a little too.

 

[Jmatlock88]

Hate to say it but I would probably cut it out and start over. Make sure the next one is trimmed to length prior to install.

 

[srmofo]

Also, o2 thread taps can be had for less than $10

 

[rslaback]

given any thought to a hole saw and an extension drive?

 

[Tim_P]

The bungs I bought were not nearly that long. I got them from Summit

 

[bad_idea]

You should be able to cut the weld w/o ruining the fitting or the header. Remove the fitting, cut down, weld it back in. Ready to go. Should be able to complete repair w/ no cost or damage w/ a good bit of effort though.