Need input for hi flo cats

[Sniper]

I believe my cats have just gave up the ghost. My sidesills are getting extremely hot.
Can someone give me some input on which hi flo cats I should go with?
I have Bellanger headers and Bellanger race mufflers with 2.5” exhaust.
Heads/cam also

 

[Steve M]

My first call would be to Prefix.

 

[Old School]

I'm no expert with cats, but I would think a Air/fuel issue might be the cause.

 

[SRT BILL]

I've installed the Jon B's high flow Ceramic cats 2 1/2" made by Belanger about 3 years ago with great success. My set up is stock headers and mufflers. The sills are way cooler to the touch and the sound was greatly improved. Since you have the Belanger headers and mufflers why not give them a call for an opinion.

 

[Steve M]

I've installed the Jon B's high flow Ceramic cats 2 1/2" made by Belanger about 3 years ago with great success. My set up is stock headers and mufflers. The sills are way cooler to the touch and the sound was greatly improved. Since you have the Belanger headers and mufflers why not give them a call for an opinion.

In this case, it would be apples vs. oranges. Sniper is running a heads/cam setup with a tune to match...the cam and tune bring large variables into the equation that's going to make it much harder for someone to make a solid recommendation unless they have a lot of experience with various setups. That's why I'd recommend contacting Prefix, although I'm sure Calvo and Nth Moto could make equally valid/valuable recommendations. The main issue is that none of those shops contributed to his current heads/cam setup, and may decline to offer advice because of that.

My personal experience with Lou Belanger was not great. He seemed to be highly opinionated and very dismissive when I wanted to do something a little different, but maybe he's a little more open to discussing different catalytic converter options.

 

[Sniper]

I am replacing my drivers side O2 upstream sensor today as I’m getting P0131 O2 sensor 1/1 circuit low code.
We’ll see if this has anything to do with it.

 

[Steve M]

That likely ain't helping matters...burnt wires?

 

[Sniper]

I don’t know yet, will dig into it about 5:00 today.

 

[Sniper]

Bad connector on upstream O2 sensor…
Hopefully this was my issue

 

[Sniper]

New connector

 

[Steve M]

Mmmm mmm mmm mmm mmm...toasty.

Any ideas how to prevent that from happening again?

 

[Sniper]

Well for one, I no longer have stock cats which will help and we’ve got heat sleeve and tape

 

[Sniper]

Well, this seems to have fixed my heat issue. We shall see.
The shaft on my shifter was also getting extremely hot and the 15 minute drive home, it was not hot to the touch.

My codes are still there but hopefully they’ll go away after a couple of cycles.

 

[Old School]

My codes are still there but hopefully they’ll go away after a couple of cycles.

A $20 OBD2 code reader will clear it

 

[MoparMap]

Cats and cams don't always like to get along I've found. I just did a cam swap on my 04 when I rebuilt it after a spun rod bearing a few years back and tried to put some cats back on it to trim the loudness just a bit. Ended up yanking them back out as they did NOT like the new cam and tune (Dan Lesser setup, so I'm pretty confident it was all done well). One day I think my cabin actually got cloudy because of smoke or something, so the cats came back out. I was just using the stock rear cats off the OE system as I've heard they are pretty similar to a lot of hi flow cats out there and others have used them with reasonably success, but I just don't think they could keep up with the flow. I was originally going too open them up to 3" on either side but found out that the 3" race muffler setup is too long to put cats in font of with headers, so only ended up opening up the front side of them to weld directly to the turnouts I had.

 

[Sniper]

It’s odd the gear shifter was getting extremely hot from bad O2 sensor.

@MoparMap-did deleting the cats make the car a lot louder with your heads/cam setup?

 

[Old School]

I've removed cats from many vehicles, most non-Viper, all resulted in significantly louder exhaust.

 

[Sniper]

Question: see pic below

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With this setup, could you remove the cats without throwing any codes or messing up the tune since both O2 sensors are before the cat?

 

[GTS Dean]

The upstream O2 reacts quickly to ambient conditions and engine loading in Closed Loop cycle. As the computer alternates from net rich to lean cycles, the downstream O2 measures the oxidation/reduction efficiency of the catalyst in action. If the computer does not sense the proper reaction of gas composition based on upstream strategy, it throws a code for catalyst efficiency. The answer to your question is NO.

 

[Sniper]

So, wouldn’t both O2 sensors being in front of the cat throw codes then?

 

[Old School]

With this setup, could you remove the cats without throwing any codes or messing up the tune since both O2 sensors are before the cat?

If you only have one cat (per side) and both O2's are upstream of it, removing that cat won't change your engine controllers' ability to detect a missing or non-functioning cat and throw a code. It will be the same as it is now. Tune wise, it could have a slight affect at WOT because of a less restrictive exhaust, but likely nothing to be concerned about.

 

[Sniper]

Yes, that’s my setup in the pic.
Headers, upstream O2, downstream O2, one cat, muffler, exhaust tip.

 

[srcody]

A word to the wise regarding O2 sensors. My 2000 RT/10 with hi-flow cats was throwing codes for primary O2 sensors. I thought I’d save some money by installing the recommended Denso sensors. Installed the Densos and continued to get the check engine light. Tinkered with a number of things and finally gave up. Took to a reputable auto electric shop. Diagnosis; bad primary O2 sensors. I was very skeptical! Shop recommended replacing the Densos with Mopars. You guessed it; problem solved.. no more codes. So by trying to fix on the cheap I caused considerable frustration and the repair ending up costing nearly $600. If I had just installed Mopar sensors to start with the repair would have been more like $150. Lesson learned!

 

[Sniper]

I put OEM O2 sensor, cleared code, and hasn't come back…

My heat is still a problem on sills so I think I’ll have to cut cats out.

 

[GTS Dean]

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[Old School]

I put OEM O2 sensor, cleared code, and hasn't come back…

My heat is still a problem on sills so I think I’ll have to cut cats out.

If you're concerned with noise, maybe replace them with something like this, if you have room

https://www.autozone.com/exhaust/performance-muffler/p/magnaflow-center-2-5in-inlet-center-2-5in-outlet-4in-x-14in-round-straight-through-performance-muffler-10416/888938_0_0?cmpid=LIA:US:EN:AD:NL:1000000:GEN:19502231967&&CATARGETID=120054150001287180&CADevice=c&gclid=Cj0KCQjwho-lBhC_ARIsAMpgMocSQPF5UP3Bvf4c1nN5Tbu6abtmUASiLbJlhNrBpuPo59Ssttm_XMMaAloTEALw_wcB&gclsrc=aw.ds

 

[Sniper]

Well, I’ve already got Bellanger hi flo cats which worked before heads cam and now they’re getting too hot. I don’t think I want two mufflers. My thought is just getting rid of the cats. It can’t be too much louder than it already is, it’s pretty rowdy!

 

[Sniper]

Here’s a clip of sound with cats vs catless, not much difference…

Viper TA Cold Startup Cats vs. No Cats

2014 SRT Viper TA. Belanger headers and exhaust. First clip is with non-high-flow cats. Second clip is just pipes and mufflers. No cats.Heading to the dyno a...

youtu.be

 

[MoparMap]

It’s odd the gear shifter was getting extremely hot from bad O2 sensor.

@MoparMap-did deleting the cats make the car a lot louder with your heads/cam setup?

It didn't make as much of a difference as I thought it would when I put them back on. Volume was slightly lower, but bigger difference was more just the "pulsy-ness" of the system. That was my problem with the 2.5" exhaust I had in general. Every exhaust pulse was pretty dramatic and had a lot of tailpipe velocity so I think you got a big "puff" that caused a lot of the noise. The cats tamed that a little bit so it was less like a chain of beats and more even, but the volume level really didn't go down enough to warrant the other issues it caused. Moving up to the 3" exhaust actually had a similar effect as it dropped the exhaust velocity a little bit and kept the exhaust pulses a little more even and subdued, though the car is far from stealthy and isn't going to fool anyone. Truthfully I think my original setup of factory cam, factory manifolds, factory cats, and the Borla 2.5" catback was probably my favorite to drive with regularly. It had a really nice low tone and a nice roar when you opened it up. The headers and race exhaust are a little more high pitched and buzzy when you wind them up, but it does sound pretty sweet at idle thumping away.

As for your particular setup with the O2 sensors, it looks like your rear sensors are mounted in standoffs. Those are used to more or less fool the sensors into always reading a nominal value so as to not throw codes. As others have said, the front sensors are more or less used for the engine tune, the rears are just there to tell whether the cats are working correctly or not. My headers have a fitting welded into them that kind of closes off the end of the second O2 sensor so it doesn't see much of the exhaust flow. It looks silmilar to what yours does, just inserted into the turnout more since mine are welded in where it seems like yours are screwed on and stacked up. You could more or less "disable" them via tuning on the older cars at least, but not sure how the gen 4+ controllers handle them. In your case I would imagine that pulling the cats wouldn't make any difference as far as codes go.

 

[Sniper]

Will deleting the cats have any performance effects on the car?
Will it make the car run leaner with less pressure from the missing cats especially at WOT?