Question about aftermarket cat odor

[Sincoln]

This question is actually for my 99' Continental, but since more here are probably changing exhausts on their Marks, figured it was better suited on this side and our engines are similar enough.

Installed Eastern Catalytic Y pipe https://www.rockauto.com/en/moreinfo.php?pk=1317925&cc=1356139&jsn=409 after the factory cats failed due a PO issue being neglectful (everything fixed, but it had a P0420, 1 cat was in chunks, a couple ignition coils were faulty along with minor rodent chew damage on the coil harness which probably caused the coil failures).

I followed the proper break-in i.e. idle 5 minutes, 2500 rpm 2 minutes to set the matting. And it probably has close to 500+ miles on it. No CEL and it appears to be doing what it supposed to. However, finally got on it a few times, and it smelled like..... well like when you eat something that throws your gut bacteria for a dive and your SBD gas smells like a sewer drain pipe for a few hours.

So more in-line with a sulfur-like smell. Pretty potent to be honest and it rolls back into the car. Car apparently came factory with the 2 up-cats like in the linked image, then AFTER the down O2's had a giant 3rd cat. Car was purchased w/o the 3rd cat (didn't realize until later as I thought the flex section it has in it's place was a factory thing).

So, would the 3rd cat scrub some of that stink out? Or do these aftermarket cats need more break-in time?

Worse case, it'll be a great deterrent for tailgaters

 

[unity]

Stink means the cats are working overtime. You have another issue someplace to address.

 

[LandYachts]

Aftermarket cat odor? Does anybody reproduce an authentic Lincoln Eau de Chat? Maybe yours just isn't car-broken.

 

[Sincoln]

I searched before posting and it appears aftermarket cats are missing some metals (nickel?) that specifically address sulfur contamination in the gas. There were a lot of people running high-flow cats that apparently have the same/similar smell and people were asking about them. Saw elsewhere a rep from one of the more prominent aftermarket companies responded they need a 500 mile break in (not to be confused with a break in to seat the ceramic by getting expansion material to expand) ideally at highway usage i.e. drive to work at a steady 65, park it, it cools, drive it home, park it, it cools x however many times needed to reach 500 miles.

@unity Engine is healthy. No CEL, no misses, not running rich, fast passed our state e-check and 86k miles. NOT a rotten egg odor which is a sign something can be wrong. This smell is like a dog fart after it got into the kitty litter box.....

Was just wondering if anyone was running aftermarket cats (for whatever reason) noticed it subsiding after enough time. Got on it a few more times today, and it wasn't strong like before, so it might indeed be the tail end of a break in period.

 

[Svets96]

I would think it would be normal for break in. I have never heard of Eastern brand types of converters. CATCO are really good, Magnaflow used to be good, I'm sure they still are, some say the matting breaks loose and shoots out the tailpipes, or just rattles.

Keep an eye on it for another couple hundred to see what it does. Take it to a trusted mechanic and explain, they can give you a good answer. I think some converter companies use different precious metals than others, than the burn off results in bad odors.

Its to bad you have E-Check. I would tell you run an off-road Y pipe. That car would really sound good with a set of Borla Pro-XS mufflers!!

Depending on where you are located in Ohio my personal mechanic is really good his name is Jack and he owns Harlans Auto Care in Canfield, Ohio.

 

[Sincoln]

Rattling means the strict initial start up break in (idle for 5 minutes, then 2500 rpm for 2 minutes, then shut it off and allow it to cool) wasn't completed or someone drove on it w/o doing that beforehand. https://www.rockauto.com/info/EasternCat/Converter Break In flyer.pdf
They line the ceramic with a material that's supposed to expand, and the ceramic will be snugged-in regardless of heat cycle, etc., but it needs the 1st-start up break in to be properly done else you get rattles, and I'm guessing eventual breakage from it pulsing constantly against the housing.

That pdf has an image of the material expanded vs. unexpanded. This break-in procedure appears to be followed by most/all aftermarket companies going by the online documentation.

I went with Eastern as they had a full Y pipe with clean bends (no kinks), O2 bungs, and supposedly higher-flowing and a touch cheaper than the next-up offering. Car sounds a little throaty at idle with stock mufflers. Was/is high quality, although for some reason their holes for the flanges were too small for the exhaust manifold studs. Might have been a year to year difference in the studs, unsure. It did fit though once the holes were widened.

Actual "round" high-flow cats, if cheapie units, can actually blow out the catalyst like a telescope. Higher-end race cats have internal designs to prevent that.

I don't mine a catted car, UNLESS it's turbo'd. They kill spool-up times Thanks Svet. I go to a muffler shop near Norton that never gripes about welding stuff (cats however are Federal crimes, so no one locally will touch them unless they are clearly damaged/failed and even then, they want OEM or aftermarket OEM-like)

 

[Svets96]

Now I know more about converters. Definitely going to keep Eastern in mind for sure. Good to hear you have a good shop to go to!

Norton isn't to far away from Youngstown, less than an hour or so. Very cool.

 

[Sincoln]

I dunno how well the Eastern will hold over time. The bends aren't as nice a factory mandrel-bent pipe, but nowhere near as bad as those crumpled bends from the really cheap aftermarket pipes. Since Ford went with a funky O2 design where one of the bungs actually sits in the MIDDLE of the firewall-side cat (actually situated between 2 rows of the catalyst if you look into the bung) it would have made no sense to just have new cats welded into the factory pipe. But it'd definitely cost more and have been a nightmare, and the CEL staying on is always a possibility any time the O2 bungs are moved from factory locations.

But yeah, sounds kinda bubbly at idle if you are close to the tail pipes. But nothing obnoxious and quiet at 5'.