exhaust nuts

[ticktack]

how do you get those nuts off of manifold that holds cat on.may have stripped one.put pb blaster,tapped with hammer,heated, and still like frozen on.there has to be a better way. two bolts and two nuts at pipe end came off easy, but manifold flange end is a , well you known what i mean.thanks for any input on a nasty job.rock on satfix!thanks

[StanW]

I would think that heat is the way to go.

[anyonomus]

Heat them with acetylene and oxygen or propane and oxygen until it is cherry red ,. Then and only then will it break loose.
You may well have to heat them two or three times as they cool very quickly.
NEVER strike them as the manifold is cast iron and will crack very easily if not done correctly.
Mentioning that .. I have on occasion split the nuts with a sharp chisel after heating.
The only other way I am aware of is to use a nut splitter like the ones linked below.
hxxp://www.northerntool.com/shop/tools/product_34573_34573
I am also not sure what a "cat" is..?????????
"manifold that holds cat on"

[dishuser]

Heat them with acetylene and oxygen or propane and oxygen until it is cherry red ,. Then and only then will it break loose.
The only other way I am aware of is to use a nut splitter like the ones linked below.
hxxp://www.northerntool.com/shop/tools/product_34573_34573
I am also not sure what a "cat" is..?????????
"manifold that holds cat on"the converter

[anyonomus]

the converter

Thanks but I was under the assumption that there was an exhaust/manifold pipe between the converter and the manifold.

[ticktack]

2001 tundra six cylinder has exhaust manifold and converter hooks directly to it near the engine, then down to tail pipe with second converter, and then out the back. thanks for all the help.will heatup cherry.

[LuckyLarry]

Toyota uses stainless nuts on stainless studs.They are famous for galling.Mega heat to get them off,but be warned:the stud & nut will probably be toast from galling.

[Terryl]

Some of the manufactures are now tack welding the catalytic converter bolts and nuts to cut down on theft, they also don't want you to replace them yourself, they want the job done at the factory service center, it's all about the bucks.

A friend had an exhaust leak just before the first converter, cost him $1550, for a new converter and manifold, it had to be replaced as one piece.

They also don't want home mechanics playing around with smog related equipment, they don't think we can do it right.