Great write up PMB has done on SS exchangers. My car is in for some work and they discovered this problem with my exchangers.

Folks with SS exchangers should give a look.

https://www.facebook.com/PMBPerformance/pho...9673193/?type=3

Important information! Please be sure to have a CO detector in the car.

Yep I have seen this issue, the ears are the weakest link on SSI's.
If damaged they should be TIG welded and the ends always need to be squared up.

Don't be a gorilla with a ratchet, get a torque wrench, if it doesn't seal up correct the problem don't just keep cranking.

If you want the piece of mind of a CO2 detector Aircraft Spruce sells nifty little stick on buttons that you can put on your speedo, etc.
They only last for about 18 months, but are dirt cheap.

I haven't been on in a while,, what's going on??

Yep. Mine looked almost that bad. There were some hard-to-see cracks around the ears too. All fixed now but was an expensive lesson.

Click to view attachment

Click to view attachment

This is a typical result of crevice cracking from the weld originally and poor fabrication and post passivation of CRES.

Don.t need a macrograph to tell.

Mine did the exact same thing.

Mine cracked as well.

Here is how to fix it. These should be TIG welded only with Argon and a large diffused gas cup.

Mark the location of the ear BEFORE removing anything.

I welded mine with a make do fixture sorry no pictures.
.I did it right before I got married.

Clean the pipe and parts THOUROUGHLY until the passive layer of the stainless is bright inside the exhaust and out.


Plug the exhaust pipe at one end and make a purge chamber from a tee on your flowmeter. This will fill the pipe with Argon so the back side of the weld will be free from oxidation or inclusions.

Reweld the ear on the fixture ....I used an old head.

Tack it all up post purging your tack welds with the TIG torch.

Weld it ALL around to avoid any crevices.

You will have to re true the mating surfaces as just this little welds will want to move the stress drawn tubing as the welding will do this so avoid avoid overheating the weld.

Sorry.... no pics but this is what I did and no problems since.

I saw this particular weld as bad manufacturing design.

Over torquing to cure a leaky he does a nice job of tearing the hoops away. Over trueing the pipe tops doesn't help. Mark with a black sharpie and use a light touch with a large file.

Both of mind cracked the same way. One was welded and I couldn't get it sealed again. Probably due to stress on one side of the pipe due to the welding operation and it's ever so slightly bent out of position. Won't try it again.
So I've bought two more. Wish me luck...................and I am using the 18ft Lb torque with a quality ratchet and ensuring there are no burrs on the fastening surface.