Is it possible my cat has gone bad?
05-20-2021, 09:56 PM
#1
Advanced
Thread Starter
Is it possible my cat has gone bad?
I think the cat on my car went bad but I was hoping for your guys' opinion on the situation so I can determine what I'm going to do next.
About 10 days ago a truck was parked blocking half my driveway, so I politely exited to the left, where there's a hump up in the pavement. The very center of my car scraped going over this hump. Looking under the car I see the catalytic converter is what's in the center, and it sticks down about an inch below the rest of the car's body, so I'm thinking that's what hit.
At first not a whole lot happened. On days 3-5 I started hearing a rattling coming from my catalytic converter area at high RPM - to me this is an earmark of a cat going bad. During this time it felt like my car was down pretty dramatic HP.
From about day 5 until yesterday the car has progressively gotten louder and throatier, and it feels like its gained back its HP or is even faster than usual. My car is supercharged so a catalytic converter blowout would likely cause a noticeable difference in HP. The exhaust also smells a lot more fuel-ey and at high-RPM I can sometimes see a trail of gas fumes chu-chuing out the quad exit pipes. There's also a TON of that sexy popping noise our cars sometimes get from the h-pipe, which I absolutely love, but can't help but think it's happening because one of my cats is more blown out than the other, causing a disparity in pressure between the two exhaust tubes.
From these symptoms, do you guys think its possible that my cat's internal honeycomb structure was blown out? Is my cat bad? It seems like I almost literally blew the **** out of the inside of my catalytic converters, clearing up back pressure and increasing HP, but I have no idea if that's actually possible. I want to get some opinions before I have the cat ripped apart. I had it looked at at an exhaust shop and the guy said there's no exhaust leaks and all the plumbing from my headers to my exhaust tips looks 100% fine externally. He didn't even mention a dent from me scraping.
About 10 days ago a truck was parked blocking half my driveway, so I politely exited to the left, where there's a hump up in the pavement. The very center of my car scraped going over this hump. Looking under the car I see the catalytic converter is what's in the center, and it sticks down about an inch below the rest of the car's body, so I'm thinking that's what hit.
At first not a whole lot happened. On days 3-5 I started hearing a rattling coming from my catalytic converter area at high RPM - to me this is an earmark of a cat going bad. During this time it felt like my car was down pretty dramatic HP.
From about day 5 until yesterday the car has progressively gotten louder and throatier, and it feels like its gained back its HP or is even faster than usual. My car is supercharged so a catalytic converter blowout would likely cause a noticeable difference in HP. The exhaust also smells a lot more fuel-ey and at high-RPM I can sometimes see a trail of gas fumes chu-chuing out the quad exit pipes. There's also a TON of that sexy popping noise our cars sometimes get from the h-pipe, which I absolutely love, but can't help but think it's happening because one of my cats is more blown out than the other, causing a disparity in pressure between the two exhaust tubes.
From these symptoms, do you guys think its possible that my cat's internal honeycomb structure was blown out? Is my cat bad? It seems like I almost literally blew the **** out of the inside of my catalytic converters, clearing up back pressure and increasing HP, but I have no idea if that's actually possible. I want to get some opinions before I have the cat ripped apart. I had it looked at at an exhaust shop and the guy said there's no exhaust leaks and all the plumbing from my headers to my exhaust tips looks 100% fine externally. He didn't even mention a dent from me scraping.
05-21-2021, 09:40 AM
#4
I had a very similar issue. The material inside of my cats was coming apart and rattling around. At time I think chunks of it would clog the exhaust causing a loss of power. I'd recommend tapping them with a mallet to verify if the noise is inside them then replace if they are the issue.
I also ended up with a chunk of the material inside one of my mufflers and had to remove the .
muffler and shake out the chunk
I also ended up with a chunk of the material inside one of my mufflers and had to remove the .
muffler and shake out the chunk
05-21-2021, 10:59 PM
#5
Melting Slicks
If one of the cats was damaged like you think, you will eventually throw a code due to the secondary O2 sensors starting to read the same as your primary sensor. That is provided they weren't tuned out for some reason.
The mallet test would be quick to do too.
The mallet test would be quick to do too.