Gene D. writes: “A couple of years ago, I had to replace the exhaust pipe on my car. When I was removing the old pipe, I discovered that the bolts holding the pipe to the catalytic converter were completely rusted, so I soaked them down in WD-40 and waited half an hour. When I tried to remove them, all I succeeded in doing was stripping the nuts almost completely round. I went to the auto parts store to see if they had replacement bolts and nuts in stainless steel. I explained my situation to the salesman there and asked him for advice on the best way to remove the existing bolts. He pointed me to a can of PB Penetrating Catalyst and guaranteed me that it would do the trick. I was a bit skeptical, but it sounded better than cutting the bolts off, so I went home and sprayed down the nuts and bolts and waited about 5 minutes. I was able to easily remove the nuts using a pair of vice grip pliers.”
We actually mentioned PB a while back when we first advised using a penetrant to loosen up old, rusty bolts, but we thought we’d share this reader’s experience as well. We have a can in the shop and have had good results with it — like when we removed the Y-pipe from Project Yukon.
Street pricing starts around $3 a can, and you can find this in most auto parts stores and big-box retailers.