Check your cats...

[shaner74]

And I don't mean the kind that meow. I have a whipple w/kooks headers & high flow cats. Well I've been working 12-hour days so haven't had any time to work on my car but I started to notice some exhaust leaks and the motor was feeling a bit "flat" I finally took a look at the cats and they were destroyed. I didn't take pics, but the centers were detached from the housing and a lot of it was melted...not pretty. I think the general consensus is not to run cats w/higher hp motors anyway, but just throwing this out there as an FYI.

[IROCanSS]

This is NO JOKE GUYS! Anyone who is blown needs to seriously take a look at the cats... I'll get someone that knows more to comment in here...

[IROCanSS]

shaner... how hot is your whipple getting? I have a buddy w/o cats and the whipple is cool to the touch after driving and a buddy with cats whose whipple is so hot you can see the heat coming off the hood and it burnt the hood liner. Only difference is the cats.

Look for a post from 2L82RUN... he has a good bit of knowledge about this. He was telling me...


and to quote the immortal words of Dan Kasky.... "Cats are for pussies"

[HufferSS]

We gutted my cats a few weeks ago to avoid future problems. I am sure the Vengeance guys have been saying that they have seen a lot of cat issues on FI cars as of late.

I am fortunate to live in a state with no visual and no emissions inspections so I just gutted mine, you may want to remove and replace with a test pipe so you can re-install at test time.

[2L82RUN]

I don't claim to be an expert but in talking to my tuner last this subject came up during our conversation. We were talking about FI motors, specifically the LS3, and how durable they have been. He told me they only recently had a supercharged LS3 come back in with problems with the #6 cylinder. When they got into it they found customers cats caused the issue. Customer was running 'hi-flow' cats with a supercharger. What happened and is occurring with other FI cars running cats is the supercharger/turbo is pushing so much exhaust that the bottleneck becomes the cats. This is causing the cats to heat up more than on a NA motor. The substrate inside the cats is expanding so much due to the heat that it is breaking down and then getting pushed, or in at least one case that my tuner saw - spun/twisted, into the cat and tries to actually push the material out of the cats. As you can imagine the material then clogs up the HI-FLOW cats causing all the heat to back up into the cylinders/motor causing some bad mojo to occur. My tuner is of the opinion that if you are running a FI setup that you need to remove the cats. His opinion of HI-FLOW cats is that they don't flow as well as the manufacturers claim. That being said, they will work fine on a NA engine, but definitely not built for FI applications. Fortunately I live in a state where they don't 'sniff' test. I just have a slip piece in my exhaust in case I would ever have to put the cats back on for any reason. I have a set of brand new HI-FLOW cats in the garage but don't plan on using them unless I would sell the car.
Like I stated earlier, I'm not an expert on this but just relaying what I learned last week. It makes sense to me that if the cat material is breaking down and plugging up then the heat absolutely has no where to go but back into the engine. I talked to Shardik2ss about this. He has a Whipple and its running so hot it burned his hood liner!! He is running cats and is supposed to get them checked. I'm waiting to see what he finds out as well.

[1 bad azz ls3]

I had to gut my cats after 1 mo with the supercharger. completely destroyed its a must do for all of ya.

[CyberPredator]

If y'all are interested I have pics of sc corvette that has blown out the cats. But it's best to just take their word for it. Hi flow Cats and boost don't mix

[CyberPredator]

[CyberPredator]

[boostedyards86]

what cats?

[gearhead440]

I running an E-Force with exhaust manifolds and stock front cats with the rear cats removed. Has anyone encountered problems with the stock cats and FI? Considering the vast majority of people are using LT headers and Hi Flow cats, I would hazard a guess that the stock cats probably have not come into question yet.

[calbert1999]

Not cool. Shouldn't the HF cats hold up regardless? Could this be busting motors from blowback into cylinders smashing valves against pistons?
I'm going to have mine checked for sure.
Exhaust manufactures should be hearing this as most people are doing HF cats with exhaust upgrades and then SC's. If CATS aren't holding up, and most places require emissions test, then it only makes sense that cats are buiilt with better materials to hold up to the heat. Perhaps, real iron instead of melting inexpensive billet aluminum, eh?

[1 bad azz ls3]

Originally Posted by calbert1999

Not cool. Shouldn't the HF cats hold up regardless? Could this be busting motors from blowback into cylinders smashing valves against pistons?
I'm going to have mine checked for sure.
Exhaust manufactures should be hearing this as most people are doing HF cats with exhaust upgrades and then SC's. If CATS aren't holding up, and most places require emissions test, then it only makes sense that cats are buiilt with better materials to hold up to the heat. Perhaps, real iron instead of melting inexpensive billet aluminum, eh?

It's not just the heat it is also the pressure from the supercharger..

[calbert1999]

Originally Posted by 1 bad azz ls3

It's not just the heat it is also the pressure from the supercharger..

Shouldn't matter; A quality CAT should not melt, here's an article I found on the subject. Hope this helps. I don't expect mine to melt, if it does me an the manufacturer going to have a deep conversation on the topic.

I might be old fashioned but if a corporation manufactures, tests, and sells aftermarket automotive products those products should hold up to what their supposed to do.

Doesn't make any sense to me that cats melt, when you need them to pass emissions.

I might be missing something here, but most cars are used for daily drivers, and many vehicles have superchargers and turbos' straight from the automaker. So, putting my ignorance aside, seems like snake oil to me when cats start to melt and the exuse is you have a supercharger on your engine. No?

Personally, if it were me, I wouldn't be destrying my cats, instead I'd be looking for a pro-bono replacement pair.

http://www.importtuner.com/tech/impp...ers/index.html

I know for some the term pay to play comes to mind, but I don't mind paying to play, but I shouldn't be paying and then being told to break the products I just bought so they won't break my engine.

[FloMoCamaro]

This is a common problem seen with hp levels starting about 600. So if your there, you might as well gut the cats and avoid any issues...

[IROCanSS]

Originally Posted by FloMoCamaro

This is a common problem seen with hp levels starting about 600. So if your there, you might as well gut the cats and avoid any issues...

600... Wheel or crank? Big difference and important.

[IROCanSS]

Originally Posted by gearhead440

I running an E-Force with exhaust manifolds and stock front cats with the rear cats removed. Has anyone encountered problems with the stock cats and FI? Considering the vast majority of people are using LT headers and Hi Flow cats, I would hazard a guess that the stock cats probably have not come into question yet.

Yes, they have caused failure on a procharged G8... Different body... same car. Blew out one of the cylinders from blowback and heat buildup.

Originally Posted by calbert1999

Not cool. Shouldn't the HF cats hold up regardless? Could this be busting motors from blowback into cylinders smashing valves against pistons?

Yes, I personally know someone it happened to. Built G8, stock manifolds/cats. Wanted a sleeper... Car blew engine...

[Black GT]

It's a known problem in the Mustang community that the KOOKS high flow cats are crap.

There have been a couple people lost their motors because of them.

[69 Rebel]

Originally Posted by Black GT

It's a known problem in the Mustang community that the KOOKS high flow cats are crap.

There have been a couple people lost their motors because of them.

Thats crazy, if that can be proven i would be looking for a good lawyer. Thankfully my cats are gutted

[IROCanSS]

Lawyer?

[69 Rebel]

Originally Posted by IROCanSS

Lawyer?

Yea a lawyer, if it can be proven the reason of the motor failure were the cats.

[HufferSS]

Originally Posted by IROCanSS

shaner... how hot is your whipple getting? I have a buddy w/o cats and the whipple is cool to the touch after driving and a buddy with cats whose whipple is so hot you can see the heat coming off the hood and it burnt the hood liner. Only difference is the cats.

Look for a post from 2L82RUN... he has a good bit of knowledge about this. He was telling me...


and to quote the immortal words of Dan Kasky.... "Cats are for pussies"

I'd look at the tune...or something else because my whipple feels about the same as it did before we gutted the cats.

[HufferSS]

Originally Posted by calbert1999

Not cool. Shouldn't the HF cats hold up regardless? Could this be busting motors from blowback into cylinders smashing valves against pistons?
I'm going to have mine checked for sure.
Exhaust manufactures should be hearing this as most people are doing HF cats with exhaust upgrades and then SC's. If CATS aren't holding up, and most places require emissions test, then it only makes sense that cats are buiilt with better materials to hold up to the heat. Perhaps, real iron instead of melting inexpensive billet aluminum, eh?

No it can't bust your motor or smash valves into a piston. It could overheat a cylinder if it plugs up BUT the engine will run very poorly and you will know something is wrong....if you keep driving it that way then you get what you deserve for being stupid.

I think much of the issue is that many tuners run their FI tunes extremely RICH in order to keep the motor from detonating and therefore blowing up.....RICH......kills the cats. It isn't the cats fault...it's the tuners fault, imho.

[IROCanSS]

Originally Posted by HufferSS

I'd look at the tune...or something else because my whipple feels about the same as it did before we gutted the cats.

He has been... been having some issues with the car. He's going to inspect his cats just incase.

We're yours plugged?

[IROCanSS]

Originally Posted by 69 Rebel

Yea a lawyer, if it can be proven the reason of the motor failure were the cats.

I know what you meant. Took me a few reads and I see you fixed it