The flange which connects the down pipe to the cat is letting loose at the weld. Any tricks other than lots of pb blaster where it connects to the manifold? The joint has fixed flanges, not spin.

Thanks

Those bolts are buggers. I took the exhaust out by way of all the manifold nuts then ground off those upper exhaust pipe bolts with a grinder. I installed the new pipe with new bolts then reinstalled the exhaust with new gaskets.

I had the same problem 2 weeks ago. I did weld a new flange on the pipe end.
Walker triangular flange model 31940 fits very well and the gasket 31383 was ok.

In order to make sure the flange will fit flat on the cat I did tack weld it to the pipe in place. I finished the welding job on the workbench after removing the downpipe.

I also drill through the cat flange to be able to use 5/16 inch stainless steel bolts with lock washers. I also use gray never seaze at the manifold nuts. I never have any difficulty to disassemble that again which happens about every 5 to 10 years.

After lots of PBBlaster over a period of time be sure you are using a 6 point 13MM socket; you don't want to use a 12 point and round off the hex shoulders.

The angle is odd in getting the socket on those nuts. I think you will want to use a universal on the end of your extension. See that the socket is straight on the nut, even a six point can slip and round edges if it is not seated squarely.

See if the nuts will move in either direction, sometimes a tightening move breaks things loose.

It is an awful location to access. If you resort to heat figure out a good way to get in there before ever lighting the torch. The yellow tank fuel produces more heat than the blue tank fuel. Once you light the torch proceed with caution.

Good luck,
Randy

Don't know exact setup, but if its the downpipe flange, just bust the bolts or grind the heads off so you can separate the flange from the cat flange. You will be replacing the down pipe, you may have the same issue at the exhaust manifold end. For manifold you use new bolts or get new studs. This job is kind of a pain that makes paying someone for their labor worth considering. Good luck. Mike