How to get those nasty catalytic converter bolts out??

[jschreiber]

Real quick, anyone have a quick way of getting those exhaust bolts out that are rusted and or welded themselves on the cat flanges with out cutting the whole cat out. Trying to salvage the flanges and just pull the cat. I hammered and used a air ratchet along with some break free spray but no go

 

[bradselph]

torch the ends off...

Other than that just keep hammering away tighten and loosen with the impact, soak pb blaster on it for a few hours you could even try heating them.

 

[purewake07]

Those are my least favorite bolts. Im pretty sure I cut/grinded the heads off on more than one occasion before i replaced them with some stainless hardware.

If no to the grinder then you'll have to wait for pb to penetrate and just keep smacking them with the hammer to loosen up the rust

 

[Silver99OZ]

I have used a lot of PB blaster along with a lot of force to break them loose. I used a nut splitter to cut off the nuts on the studs on the back of the cat. Heating the nuts/bolts with a torch until they turn red and then use a breaker bar on them works well too.

 

[rx7ttlm]

Real quick, anyone have a quick way of getting those exhaust bolts out that are rusted and or welded themselves on the cat flanges with out cutting the whole cat out. Trying to salvage the flanges and just pull the cat. I hammered and used a air ratchet along with some break free spray but no go

Times like that I grab a reinforced cutting wheel (die grinder with 3-4 inch cutting wheel) and just cut the bolts off. I don't even mess with trying to break them loose.

 

[jschreiber]

Times like that I grab a reinforced cutting wheel (die grinder with 3-4 inch cutting wheel) and just cut the bolts off. I don't even mess with trying to break them loose.

So once the bolts are cut, assuming on the head, how to get the rest of the threads out? Or are the threads only on the cat side so the head falls off and theres just a hole after knocking the cat off?

 

[tmaxx411]

could you take a picture so we know exactly how bad they are?

otherwise a torch is your best bet. get the nut cherry red and try to loosen it. impact will probably either strip or break them, and i've never seen pb work on exhaust hardware

 

[99ECLIPSEGSXDSM]

Cut the nuts off then it should have a little room to play with. Pull the stock catback out then pound the bolts that are still on the cat. I didn't want to deal with that crap so I said screw it and orderd a dp and pulled the entire system in two nuts just about.

 

[jschreiber]

Cut the nuts off then it should have a little room to play with. Pull the stock catback out then pound the bolts that are still on the cat. I didn't want to deal with that crap so I said screw it and orderd a dp and pulled the entire system in two nuts just about.

Good call on the dp. Was waiting on doing whole exhaust for awhile. Anyone know if a dp will fit onto the stock exhaust.

 

[campos_racing]

Best way is to put the torch on them, heat them up so the bolt becomes softer/shrinks. IMO if its not smoking or doing damage to your car, invest in a full exhaust or the cat will entertain you there for a few hours.

 

[northernawd]

could use a torch and warm it all up and see if it will allow to 'crack' the nut. would become easier to grind the nut off too, as mentioned above the metal would become softer.