Catalytic Converters & Boost.. Disaster waiting to happen? (Street / Strip )

[15Oxford5oh]

What's going on fellas,

As the caption says I'm looking for a little bit more insight on if my cats will hold up or is this just a ticking timebomb on borrowed time. I recently just boosted my car and I'd like to take it to 1/4 and see what it does since my new found horsepower has arrived. Nothing special.. GEN 2 G3. 115M. PUMP GAS(93).

I currently have Stainless Power LTH High Flow cats and I am hoping to run the car in the next couple of months maybe once or twice a month. I have been reading horror stories of Cats overheating and failing, taking the motor with the failure and would like to avoid this at all cost, as I'm sure all of us are. Yet, I do see quite a few boosted cars still running cats? What is the culprit of the longevity of keeping cats on the car vs me just getting rid of them now? What is the smartest option to do and will i run into issues with tuners tuning for Cat deletes?

I'd like to keep them if able, as the wife hates the smell of catless exhaust. I could careless but i'm sure i'll have to start sleeping outside if I kept that behavior up. Looking for insight, thanks in advance.

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[engineermike]

Totally depends on tune and driving style.

 

[Proshop]

Brian I went catless as a precaution because I had read about all the issues people had with cats clogging up when boosted due to the richness of the tunes. I also wanted as much flow as I could get thanks to the guy above me @engineermike thread about pressure testing. As for the wife issue I went through the same thing with mine but over time she has quit harassing me about the smell and rarely rides with me so it worked out.

 

[stang17]

The only cats I would run if boosted are the GESI green cats. I've had my whipple since day 1 dealer install/wrapped into financing. In a few thousand miles stock cats started to fail (smell like sulfur and then upon inspection were starting to collapse and melt together). I replaced with Kooks 1 7/8 regular high flow cats and they failed within 700 miles. In whipple's defense, they did provide a tune update to resolve the cat failing issues after the fact.

Also, to my knowledge, there is not a cat that can hold up to repeated 2-step engagement whwn launching.

I've personally seen 2 engine failures in our local race group due to clogged cats.

 

[15Oxford5oh]

Brian I went catless as a precaution because I had read about all the issues people had with cats clogging up when boosted due to the richness of the tunes. I also wanted as much flow as I could get thanks to the guy above me @engineermike thread about pressure testing. As for the wife issue I went through the same thing with mine but over time she has quit harassing me about the smell and rarely rides with me so it worked out.

Thanks for the insight, I see you also have the stainless power headers as I do. Did you use the transition tubes (in place of CATS) if so, was it the hole for 02 sensor tube option or no? And also what did you do about the check engine light? Defoulers in place for the rear O2's?

 

[15Oxford5oh]

The only cats I would run if boosted are the GESI green cats. I've had my whipple since day 1 dealer install/wrapped into financing. In a few thousand miles stock cats started to fail (smell like sulfur and then upon inspection were starting to collapse and melt together). I replaced with Kooks 1 7/8 regular high flow cats and they failed within 700 miles. In whipple's defense, they did provide a tune update to resolve the cat failing issues after the fact.

Also, to my knowledge, there is not a cat that can hold up to repeated 2-step engagement whwn launching.

I've personally seen 2 engine failures in our local race group due to clogged cats.

Yea that's definitely a worry of mine, and listening to the feedback looks like it's best to just remove them before a premeditated problem occurs, now would be figuring out the best way to get rid of the cats and avoiding a check engine light in the process.

 

[DougS550]

The only cats I would run if boosted are the GESI green cats. I've had my whipple since day 1 dealer install/wrapped into financing. In a few thousand miles stock cats started to fail (smell like sulfur and then upon inspection were starting to collapse and melt together). I replaced with Kooks 1 7/8 regular high flow cats and they failed within 700 miles. In whipple's defense, they did provide a tune update to resolve the cat failing issues after the fact.

Also, to my knowledge, there is not a cat that can hold up to repeated 2-step engagement whwn launching.

I've personally seen 2 engine failures in our local race group due to clogged cats.

I'm surprised no one has engineered an adjustable CAT Bypass Valve you could weld to the CAT Inlet Pipe, install one differential sensing line in front of the cats and one just after the cats. And If or when the Cat becomes clogged the Valve would sense the differential pressure differences between the two and open, releasing the PRE-CAT Exhaust Pressure/Flow prior to the cats. Then You would have piece of mind that if one of your CATS clogged, Your engine would be protected by the release of PRE-CAT Exhaust Pressure. This way you could stay within EPA guidelines for your state (If You Are concerned About that). JMHO

 

[Angrey]

I'm surprised no one has engineered an adjustable CAT Bypass Valve you could weld to the CAT Inlet Pipe, install one differential sensing line in front of the cats and one just after the cats. And If or when the Cat becomes clogged the Valve would sense the differential pressure differences between the two and open, releasing the PRE-CAT Exhaust Pressure/Flow prior to the cats. Then You would have piece of mind that if one of your CATS clogged, Your engine would be protected by the release of PRE-CAT Exhaust Pressure. This way you could stay within EPA guidelines for your state (If You Are concerned About that). JMHO

It would only apply to people who want to follow the intent but not compliance with the law. It would NOT be EPA "lawful" because anything that modifies the OEM exhaust/evap/emissions, etc is a violation. All that junk is certified prior to them selling the first vehicle/model.

So in the end, you'd still have an illegal modified exhaust and it might protect against drastic failure, the only person you'd be satisfying is yourself. Very few car guys care enough about emissions and EPA compliance to go through the efforts you outlined.

 

[DougS550]

It would only apply to people who want to follow the intent but not compliance with the law. It would NOT be EPA "lawful" because anything that modifies the OEM exhaust/evap/emissions, etc is a violation. All that junk is certified prior to them selling the first vehicle/model.

So in the end, you'd still have an illegal modified exhaust and it might protect against drastic failure, the only person you'd be satisfying is yourself. Very few car guys care enough about emissions and EPA compliance to go through the efforts you outlined.

True, such as me but: their are some guys I would guess would. IMO

 

[engineermike]

Take it one step further and make it a boost operated bypass valve. Cat works all the time but you get like a 2” bypass around the cat element when in boost. I’m sure it wouldn’t technically pass inspection but would meet the intent and keep odors at bay.

 

[15Oxford5oh]

Take it one step further and make it a boost operated bypass valve. Cat works all the time but you get like a 2” bypass around the cat element when in boost. I’m sure it wouldn’t technically pass inspection but would meet the intent and keep odors at bay.

One could hope they would one day implement a system like that, in the meantime I have no inspections to pass and the EPA isn't gonna help my car stay the safest and run efficiently so I'll likely look into a set of defoulers and welding in a straight pipe where cats are.

 

[DougS550]

Take it one step further and make it a boost operated bypass valve. Cat works all the time but you get like a 2” bypass around the cat element when in boost. I’m sure it wouldn’t technically pass inspection but would meet the intent and keep odors at bay.

I can't imagine affecting emissions when not bypassing. I'm still on the fence to if I will remove or Green high flow cats. Take Care

 

[Proshop]

Thanks for the insight, I see you also have the stainless power headers as I do. Did you use the transition tubes (in place of CATS) if so, was it the hole for 02 sensor tube option or no? And also what did you do about the check engine light? Defoulers in place for the rear O2's?

Mine came with the off-road connection to factory pipe since I ordered them catless. Not sure about the 02 bungs maybe the pic below will show. Looks like just fronts.

 

[Avispa]

How much track use are you planning? If it's just an occasional test and tune visit, you aren't likely to get in any trouble. The cats aren't going to plug on the first or second run at the drags. Your boost gauge should give you more than fair warning of any plugging. Changing from Flowmaster 40s to Magnaflow dropped my boost pressure 3#. Your cats will be a long way from failure at 3# more boist pressure. For reference I put over 50000 miles on my last Terminator after putting on a Whipple 2.3., which was at 125000 vehicle miles. The boost never budged.

Funny how people's perceptions change over time. You can smell a decatted car several car lengths back. Back in pre cat days (dating myself here) all cars smelled like that and you wouldn't notice.

 

[Zrussian13]

Mine came with the off-road connection to factory pipe since I ordered them catless. Not sure about the 02 bungs maybe the pic below will show. Looks like just fronts.

It looks like the rears are on the horizontal right before the 90s going into your x pipe.

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