2011 LC Catalytic Conv. Flange rot - gases escaping - options to fix without full CC replacement

[UVNH]

2011 LC in heavily road salted NH.

Failed inspection with exhaust gases escaping from rotted flange on catalytic converter. Recommendation is to replace catalytic converter ($2K part). CC is not setting off any check engine light so is presumably otherwise working fine.

I need to get underneath and get some pictures, but assuming the flange is not a separate part my question is can this problem be repaired without replacing the CC?

Maybe a custom muffler type shop can cut away the rotten flange and custom fit something to reconnect?

Any ideas welcome and I will get some pictures.

Thanks!

 

[CharlieS]

I would also think that a good muffler shop could cut off the flanges and weld in a new section with a new set of flanges.

 

[bloc]

You and Charlie are on the right path, a good exhaust shop can sort it out. With the salt in your area I'm sure there are plenty of shops used to this work.

Alternately if the pipes are relatively straight in the area you could cut out the flange with a sawzall and run an exhaust clamp sleeve, as long as there is one in the right size. They don't have a very wide range of adjustment while staying leak-free, but are super easy to use and a very solid way to attach exhaust pipe. And high quality ones are only $35 from Vibrant Peformance. I used these and band clamps on the exhaust for the LS-swap in my 80 and they worked great.

One issue with having an exhaust shop replace the flange is potential weld quality issues in the harder to reach areas, and the welds and flange will be mild steel and very prone to rust. Though by the time that is an issue other corrosion with the exhaust may force other more substantial work anyway.

 

[kng]

I own a muffler shop and cut out Toyota flanges daily, then weld in a small piece of 409ss with a welder that has
308l ss wire. 20 minutes if they are good welders. "typically" a small local shop would be more inclined to have a
good fabricator than a large chain shop. One can have the flanges welded in also its more time and money for
little gain if your not removing exhaust regularly.

 

[bloc]

I own a muffler shop and cut out Toyota flanges daily, then weld in a small piece of 409ss with a welder that has
308l ss wire. 20 minutes if they are good welders. "typically" a small local shop would be more inclined to have a
good fabricator than a large chain shop. One can have the flanges welded in also its more time and money for
little gain if your not removing exhaust regularly.

Curious what shielding gas you use, and whether you purge the back of the weld of air also?

 

[kng]

Curious what shielding gas you use, and whether you purge the back of the weld of air also?

we mig weld with .030 308l wire, the gas is a tri mix. argon, helium, co2

 

[bloc]

we mig weld with .030 308l wire, the gas is a tri mix. argon, helium, co2

Thanks. I used trigas building the exhaust for my 80 and it worked pretty well but didn’t know if there was something better.

 

[UVNH]

I own a muffler shop and cut out Toyota flanges daily, then weld in a small piece of 409ss with a welder that has
308l ss wire. 20 minutes if they are good welders. "typically" a small local shop would be more inclined to have a
good fabricator than a large chain shop. One can have the flanges welded in also its more time and money for
little gain if your not removing exhaust regularly.

Just to close this question out, I had a mom and pop muffler shop do the repair for $80. Much better then a new CC. Anyone in Northern New England, I can recommend "Low Cost Exhaust" in Rutland Vermont.