How do you get old rusty exhaust pipes loose?

[troutwest66]

PB rides in my truck, too.

 

[tuckerd1]

Never used it, but I will get some. Sounds too good not to try!

 

[gotdiesel?]

You will not be sorry. PB is the best stuff in the world. I don't know what relevance the styrofoam cup test has, but that's what sold me!!!!

 

[Guntherx]

I bought a gallon can at Tractor Supply in Westminster, MD and it came with a refillable spray can. Really cheap that way. I have proved this stuff over and over and over and over. Did I say over and over?
Just put it on at least 1/2 hour before you're ready to start and it should do the trick.