Hey guys, here's the scenario...

My 2000 Disco (176000 miles, 4.0L, top end rebuilt @167,000) has developed a sound something like an exhaust leak. It seems to be located near the driver's side (USA) catalytic converter. I had it running and slid under with a flashlight for a look around. No visible leak but the sound was definitely coming from the cat. It progressively gets worse until the engine reaches temp. Almost not noticeable when the engine is cold. It's still running fine, but noisy. Also, the sound is not the typical ticking exhaust leak sound, it's has more of a throaty deep sound combined with the ticking exhaust sound. Is this just a leak or corrosion up behind the heat shield? I live in Reno Nevada, almost no humidity to speak of, made me rule out corrosion. Just wanted some advise before I start tearing into the pipes...

 

Do a SeaFoam induction cleaning and it will blow smoke out of every tiny crack it can find. And kill skeeterz for 100 feet...

 

LOL...exactly how I figured out I had a leak where the downpipe meets the cat! I thought there was one (ticking was noticeable on that side) and did the seafoam and finally was able to see it.

 

I'll let you know what I see when the SeaFoam is fuming! Thanks all!

 

have a rag handy as you will need to partly block the exhaust, that will create enough back preasure for you to see where it is leaking

 

The leak is, in fact, on the driver side (USA) catalytic converter. After more intense inspection, I found it. I also found a place online that sells the downpipe assembly delivered for $322 (you can offer a lower price than listed, I offered $300 they accepted $322). Great deal. Link below.

Davico 18098 49-State Federal Emissions Legal Direct Fit Catalytic Converter - WCP Diesel

 

That's a good price. You might be able to get away with a weld-in converter from an exhaust shop. Also, keep your old cats for recycle. You can get a pretty good price for them.