Best way to start on rusted exhaust nuts (wrench vs impact) without destroying it?

[TerryMason]

I need to take apart a section of exhaust on my mom's Ford Escape - it's only four nuts, and they don't look too bad. I've been hitting them with PB Blaster for a day or two, and I'm about to the point where I want to take them apart.

I've got a hefty 1/2 inch Dewalt impact that would likely make short work of this, but I was wondering if it's better to start with a standard socket wrench before going straight to the impact? My goal would be to not break the studs off the exhaust.

I've got a torch that I use for plumbing, but it's not something that I often use on the car. I would likely only use this as a last resort.

My current plan of attack is to start with a socket wrench, if needed move to a breaker bar, and finally impact gun.

 

[mark sr]

Are these the bolts for the catalytic convertor? If so, how old is the car?

 

[superj]

i have found the best way to loosen stuff like that is with the longest breaker bar i can find so i can apply smooth easy torque. turn it a little and then turn it back the other direction to clear the threads. than turn it some more and go backwards to clear the threads. just keep doing it till it comes off

 

[TerryMason]

Are these the bolts for the catalytic convertor? If so, how old is the car?

No, these are on a Y pipe. Only thing that connects into it is an O2 sensor. I need to remove this portion of the pipe in order to drop the oil pan.
Car is a 2009 Ford Escape.

 

[TerryMason]

i have found the best way to loosen stuff like that is with the longest breaker bar i can find so i can apply smooth easy torque. turn it a little and then turn it back the other direction to clear the threads. than turn it some more and go backwards to clear the threads. just keep doing it till it comes off

This is what I'm thinking, but I read on another form that you should start with an impact because the vibration can help loosen things. I'm tempted to use your method though.

 

[mark sr]

start with an impact because the vibration can help loosen things

I've always found this to work well but you need to keep it in short bursts if you are concerned about breaking the bolts.