so im currently trying to uninstall the stock exhaust and replace it on my 07 si 4door. unfortunately all the bolts are rusted to hell (bought the car used and i think i came from the east cost where they use salt to deice the roads, which may have caused the rust). So i already snapped one bolt and some of the others i cant budge at all. I just got some liquid wrench and a wire brush and took that to it, and now im letting it settle for a bit. But if anyone has any tricks that could be useful that would be great!

 

a torch, cut them.

 

PB Blaster....works great on rust.

 

x2 on PB Blaster

 

well i was able to get most of the exhaust off. I could only take it off in one peice tho cuz i still couldnt get the 3 bolts from the rear end of the cat off. Still need to accomplish that. so i got it off from the header to the axel and then i discovered a problem. Apparently whoever had this car before me decided to have a muffler not designed for this car welded on to the axle back. doesnt sound that bad except for whoever did this put in a custom hanger braket and welded the hanger to it to keep it in place, since it wasnt for this car it didnt go to the stock hanger.
I dont have a torch so the best i deal i have is to get a little hack saw and try to saw through the quarter inch or so hanger. I ve never seen anything like this and i dont know why someone would do that to an 07 si. i'll try to put up some pics and let u know how it goes. you guys are gonna laugh tho.

 

yea try a hack saw for the hangar, they are pretty inexpensive and work well

 

take it to an exhaust shop and have them break them loose. you need to head them up with a torch.

 

Yea, I have the same problem on my brother's 93 Accord SE. Guess the blowtorch is my next step, as I don't see a way PB's gonna save me on this one.

 

dear god! mine doesnt look like that, but they are stuck fast. im about to go work on it, ill update later

 

LOL, and here I thought it was common to be that bad. I guess common for the fact that its 16 years old.

My brother's situation is that the downpipe has rusted away and the flex area has multiple holes. Bought an eBay header+downpipe kit as I couldn't find an intact one at the junkyard...and yes I know the horror stories and I gotta say the one I got was pretty damn cheaply made.

I got enough pics for a tutorial now....maybe should make a quick one as I don't see one in the Accord forums (I know its not that complicated, but hey it's always nice to have it for the newcomers like me. )

About to blowtorch it now after this post and saw it off (downpipe side). I hope I can retain the cat as I'd rather not buy one.

 

oh wow. thats on another level.

 

My exhaust is only a year old and already showing signs of rust

 

My OEM exhaust was much worse than that =/ try a '94 civic EX that has been in wisconsin and daily driven for all 15 years. My exhaust piping right after the cat actually broke while I was driving it, and I don't even need to tell you about the bolts =P

 

ok so i got my new exhaust on but i still cant get those damn rused bolts off the CAT of the stock piping. i wanted to keep that piece of pipe with the cat just in case i want to put it back on. i ve tryed this stuff that dissolves rust, beat it with a hammer, and i still cant get any of the 3 bolts loose. the section of piping is too big and dirty to put in my car to take to an exhaust shop. maybe i should start asking around the neighbor hood to see if ne one has a torch?

 

This is common in ironwork just on a larger scale. If you do this right with a torch(fire axe) you can actually heat the nut up really fast and cut just the nut off leaving the stud. It is really hard to explain but if i need to i will.

 

do you have a dremel? cut the bolt heads or nuts off. You can pick up a nice one and a diamond wheel for like $60-$100.

 

1 and half years and no rust =]
the glory of the desert

 

Well, if it helps any here's what I did with my brother's 93 nightmare Accord. You saw in my pic how bad it was so this should work for you as a last resort. I ended up doing something similar to what alphalanos said:

Instead....I didn't use a dremel although I would suggest one if you do have access to it. I used a Jigsaw with 14 TPI jig head (metal cutting of course) to cut the bolts off and then hammered the remainder of it out with a BFH (4lbs). This required substantially a lot more work, such as taking off the rest of the exhaust to do the hammering more efficiently but it worked. Had to heat up some of the bolts with a torch to help get them out but I'm hoping you don't have to apply so much "love" to yours. Because the cat heats up to extreme temps and environments apply their layer of rust and grime to coat it, the usage of heat will help loosen things. You may want to find an Acetylene torch as my propane torch worked but took way longer. Make sure that if you do choose this method that you cut as close as you can to end of the retaining bolt. I had to use a grinder for the one I missed with an old Rotozip grinding attachment.