Hey guys,

So I was working on the Max over the weekend and decided to look for the exhaust leak with some tubing and a funnel... well after about 45 seconds or less I found where the leak is. The rear passenger side bolt is sheared off... I already ordered new gaskets for the cat but I am not sure what size bolt I need? From what I measured I should be able to drill that out with a 3/16ths but I could be wrong... Any input?

 

if its on the main cat they are just studs you can smack them right out. 12 x 1.5 i think for the

 

It is the main cat, on the resonator side. But I ordered both gaskets I want to just go ahead and change both while I am down there.

 

You could try to knock the stud out, good luck. If you can't get it the first few licks, then drill it. Nut and bolt will hold it just fine.

 

I would suggest stainless nuts and bolts, they seem to last longer and will come apart when you need them to. Good Luck.

 

16 yr old stud bolts here gotta heat those suckers up and blast them with a penetrator before you go at em.

 

OK well I have hit them with PB I am going to attempted getting it out tonight after work... I have my torch ready if need be I have map and propane... I was planning on heating just the nut to try and break the rust up... but that one bolt is already
broken am I going to be able to knock it out or will I need to drill it? I will get 4 bolts and nuts just in case but I am not looking forward to it lol.

 

Good Luck Man...

 

It's not a whole lotta' fun. I just did it. I'm betting you're going to have to drill those studs out. Like previously mentioned, nuts and bolts work just fine.

 

OK well I have my grinder on loan to a friend... for bolts I prefer to grind flat and then drill it out so I guess I will just wait...

 

I just noticed you're in Cali, you might just get them out with some heat and some luck.

 

Yeah well one is already snapped off right at the flange... I will probably try my bolt extraction kit. The snapped bolt is the source of the original leak

 

In that case, get the drill out.

 

Well i isnt have time to dive in today so friday evening is it i guess.

 

In my experience, even if the nuts come off the studs, the amount of corrosion on there will only screw it up more later. I'd remove the studs, hammer or drill, however you want, and replace them with stainless nuts and bolts, as others have already posted.

 

I had to drill mine out. I tried the hammer with the cat off the car with no luck. It was a pita to drill fyi. I did the grind flat and drill process.

 

Yeah many ways to do this, one of mine broke out with the nut, the other I used a Dremel with cutting wheel to cut off and just drilled through.

 

Not a lot of room to get the drill in there. It is indeed a PIA. 18v Milwaukee battery drill got it done for me.

 

just installed a cat-back about two wks ago and broke both bolts off cat. went to ACE hardware to get the best 5/16th drill bit or buy a titanium bit set and it took about 30-45 minutes and 2 batteries to drill out. once it's drilled out ream the hole out to the size of the bolt and you should be good. hope you get it out.

 

I am no stranger to drilling out bolts and rivets it is a pain... But I have my air drill and my Dewalt with 2 batteries so I think I will manage lol I will let you know how it goes... lol

 

I dont remember what it looks like down there but are these just studs with nuts? IF so do the studs stick out of the back? I was wondering if I could just weld a not on the stud and back it out?

 

Well I spent about an hour out there with heat pb blaster an my impcat wrench... all that came from that was two stripped nuts.. lol I am still waiting for my grinder to come back so I cant drill them out right now.. not happy lol

 

Oh also tried my 6ft breaker bar... No go!

 

what kind of torch do you have? How long did you heat it for? Its easier with 2 people if you hadnt already stripped it lol. One person heats for a min or 2 and then the next is ready with the, preferably, impact wrench to go at it. Cant wait because it cools down fairly quickly from the heat that it needs to be at. Your not using an open ended wrench to try to get it off are you?

 

I was using an impact socket, I was heating with mapp gas for a couple minutes with the impact wrench ready but it just stripped right off the bat. Then on the other one I tried the breaker bar and same thing stripped.

 

its possible your not heating it up for long enough? I've never seen a bolt that is impossible to get out per se, just difficult. I would of sprayed it like a **** and let it sit for 30mins or so. Then heat it up for about 3mins and right after go at it with the impact. If that is what you did then get a saz-all and get a brand new section lol. SOunds like it doesnt much matter now anyways because they are stripped already

 

Normally I would just use my grinder and drill the studs out when I have the cat out but I don't have it right now so... Guess I will wait.

 

There are stud bolts down there btw so your welding idea might work as well

 

I ended up using the Grinder and then drilled the studs out. About an hour from start to finish. No more leak at the Cat, but I still had a leak further up. I discovered that two bolts were missing from the front pre cat heat shield so I put bolts bin there and it made a big difference, But I still have another leak, it sounds like its coming from either the flange between the front precat to the rear or the flange from the rear precat to the exhaust manifold but I can't pinpoint it.

I decided to fix the egr while I was at it, the previous owner tried to take the tube out but didn't know you have to hacksaw the bolt on the tube closest to the firewall. He didnt bother to put the nuts and bolts that he took off back on so there was a major exhaust leak there. I cleaned the egr tube (completely clogged) as well as the throttle body and everything else I took off. Check engine light is gone but I have only driven about 20 miles so far...

All in all it was an ok day, six hours or so but I still have an exhaust leak although its vastly improved. Still have my airbag light that I can't seem to get rid of (removed seat and re installed causing the airbag light to trigger). Now the front bearings are even more noticeable since the exhaust isn't as loud as it was. The previous owner was an idiot, anything I have had to fix was previously worked on and not put back together correctly... tons of missing bolts, clips, nuts and clamps. Not fun.