Are you running catalytic converters or not with boost?

[Milktasd]

have seen a couple of people say no issue running cats and quite a few say it’s a time bomb if you don’t get rid of them.

trying to plan my stage 2 whipple build on what all I need to do when adding blower vs what can wait.

not opposed to running no cats due to no emission checks down here.

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[robvas]

The kooks cats

 

[engineermike]

I’ve failed several stock cats. They are very delicate.

 

[SnowFox]

Running stock Cats of my S/C

Right now they operate perfectly fine. If that ever changes I'll cross that bridge then. But I never saw the point in replacing them before they actually go bad UNLESS chasing down more power. That or its somehow causeing a issues someplace up steam.

 

[Unas2k5]

Depends on your power level but I’d you’re up there your cats can melt and your motor can be a risk for detonation.

 

[engineermike]

Most of the ones I’ve failed came apart little at a time. The first brick fails and the free bits beat themselves into powder and pass through the rest of the exhaust causing no real harm, then you get the p0420/430.

I did have one brick disintegrate all at once, clogging the second brick and causing a log jam. The benefit of running speed-density really showed up, as the boost spiked which caused the controls to pour in fuel and pull spark. It was plugged so bad that it caused the bank1 vs 2 fuel trims to skew (airflow imbalance due to back pressure) and a misfire.

 

[engineermike]

F-150 cat

 

[engineermike]

Mustang gt

 

[engineermike]

You can see cracks starting to form in these.

 

[mejohn50]

I toasted both stock GT cats when I had the Whipple on my 2019. One started to come apart like the pics @engineermike shared and the other just had cracks but I had P0420 and P0430.

 

[robvas]

Can you bash them out with a broomstick or pry bar when that happens?

 

[engineermike]

Can you bash them out with a broomstick or pry bar when that happens?

Sort of. The drivers side doesn’t have a flange so you can’t really access the bricks without cutting and welding. Also it causes problems with the diagnostics and control logic.

 

[djcodeman]

My cats clogged. Luckily motor didn't go boom. Went cat delete route.

 

[DF19RS3]

Had mine replaced under warranty several times within 5-7K miles. Now the new ones hang on the wall. When I sell the car they can go with it. Until then it opened up.

 

[SpeedLu]

Installed a centri supercharger and ran with stock cats for 3 months until they burned up. Engine blew at the same time. Rebuilt the engine and installed long tubes w/high flow cats, and it's been years now with no issues.

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