Cold engine, engine off, blow air into the exhaust. Block any open tailpipe, Use a wet/dry vacuum to make a blower, or a Kirby vacuum (that's what I used). Get the exhaust system pressurized.

Soapy water in a spray bottle, and spray the exhaust joints and sensors in the exhaust you can easily get too and see if it bubbles. Found my exhaust leak at the turbo charger EGR pipe flange. ~$20 for flange gasket and two new bolts.

It's really easy to see where it's leaking in a few seconds. Took me under 10 minutes to set it up and check. Lucky I found mine fast. Good luck.

 

Great, will try that next. Thank you for the suggestion.

 

I think I found the leak. I appreciate the suggestions. See video and pic. Question now is: is this cat toast or could it just be the gasket?

 

Almost looks like the flange is not welded. Does it look right?

 

Perhaps someone that remebers how this output flange is put together can offer some more info, but I think that is just a reinforcement plate that goes behind the actual flange to strengthen it... you can unbolt it to inspect. However, there should be a flange underneath it, and if it's leaking from that side, likely has a crack or hole in there somewhere. If so, you can probably just get it welded up, the cat itself should be fine.

 

 

Good catch, Oh yeah, that's leaking, mine was just under the turbo on the smaller EGR pipe flange, but at the gasket.

I wonder if that new engine swap had already had that leak when the engine was put in. Or was it damaged by the installer through stress on an exhaust pipe when installing. You'll never know which.

I think you will have to see if it is cracked, and if so maybe it can be welded. But CHECK the nut tightness first, maybe you get lucky and they didn't tighten the bolts. Try that first.

The shop that installed this engine should have some kind of engine warranty. Take the video to them.

 

I already took the car back after the initial swap and they pushed back. I am for certain there was no leak prior to the swap. I think I can fix it on my own and I appreciate the feedback thus far. I'm considering taking out the pipe and getting it welded but might try just a new gasket just to be sure before the pain of a cat removal. I had a friend look up the torque for the bolts and he told me 10 nm. If that's the case its not much more than hand tight but that just doesn't seem right.

 

I had this same problem under warranty. Soot on the aluminized heat shield. Appeared to be a hairline crack in the manifold. Dealer missed it. Eventually they replaced it.
it’s stainless replace or get a good welder to repair it. Flange has to be pretty flat after welding though otherwise it won’t seal.

Also check for injector seal leak or leaking intercooler tubes.11

 

I had a shop weld where the leak was and just got back from a 1000 mile trip. Seemed to do the trick. Appreciate the feedback