Yesterday I successfully removed the dreaded 2 nuts fastening the catalyst to the y-pipe. The car rode for seven winters in salty and rusty environment. So you can imagine how bad the nuts were.

To get those nuts off, one solution mentioned often here is to take the car to a garage and have them cut the nuts off with a torch. What I did was, using a dremel with a grinder wheel ( small 1" diameter), I cut a slot in the nut to split it open. Then a applied a few drops of penetrating oil. Finally, I twisted off the slit nut with a vise grip. Pretty easy job, but I must admit I had the whole y-pipe section and catalyst off the car, and was working on a bench. The dremel tool being small, I dont think it would be difficult to use it while the cat is still under the car though. While cutting the nut with the dremel, it's difficult to avoid cutting a small bit of the threads off the underlying stud, but it was just a small cut not big enough to prevent reusing it.


For those of you replacing the y-pipe, or any other stubborn nut or bolt for that purpose, a dremel is an inexpensive tool ($40) that does a lot for you.

 

Can you post a diagram of how you cut a 'slit' in the nut?

 

you taka tu muffla shop young grass hoppa.

 

Or you can buy a nut splitter.

 

Thanks for the tip.

I have to say, one thing I've learned a lot about since starting to work on my car is how to handle PITA rusted/seized bolts and nuts.

The next good tip of the day is to have helicoil kits in M6 size to fix all the stripped threads that come so easily in import cars. Excellent for holes tapped into aluminum.

Dave

 

I'll post a pic tomorrow.

 

this thread is just begging for a bad pun joke

 

I just stick the socket on and break them....literally.

 

any success with the helicoil kit?