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Discussion Starter · #1 ·
I have a 2017 Sti I’ve deleted the mufflers and hammered out my cats long ago I want to install a aem cold air intake I’m wondering which ots tube I can use safely I’ve searched and searched on here and I’m seeing so many mixed answered I have had my ap for over two years and never have I upgraded the software pounding out my cats has t caused any check engine lights any help would be appreciated
 

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Some punctuation would help.

Secondly, you're seeing mixed answers on whether or not a Cobb OTS tune will work with a non-Cobb intake? Strange...

Never heard the term "hammered out" or "pounded out" in regards to cats. You mean gutted? That should've thrown a CEL. No way getting around tuning for no cats, let alone aftermarket downpipes.
 

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Discussion Starter · #3 ·
Some punctuation would help.

Secondly, you're seeing mixed answers on whether or not a Cobb OTS tune will work with a non-Cobb intake? Strange...

Never heard the term "hammered out" or "pounded out" in regards to cats. You mean gutted? That should've thrown a CEL. No way getting around tuning for no cats, let alone aftermarket downpipes.
Sorry about the punctuation! I was falling asleep lol . And I call it hammered out cause that’s what I did ! I used an air hammer bit and went to town on both . I didn’t have to cut either of them open. I have had my car this was for 6 months and no cel at all. I’m going to find a tuner and do it right before installing the intake . Thank you for your help
 

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What was the point of pounding out the cat? It's not a power bottleneck in the stock exhaust.

Yeah you have to have a tune specific to the installed intake.
 

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I’m seeing so many mixed answered
I'm not surprised in the slightest. This is why I refuse to buy a used turbo Subaru...

You should remap the ECU if removing the catalyst internals. Saying "there isn't a CEL" isn't enough. You can completely blow a motor without a single CEL illuminating. That modification is also highly illegal on the street so if I were you, I'd keep quiet about it....
 

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Know what else sounds better? The sound of your car actually running and not blowing it up.
 

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One vape away from a tragic stereotype. Surprised the poor car has held up for 5yrs.
I don't understand why the intake thing still causes confusion. Even reddit has mostly come around.

The exhaust thing baffles me even further. I don't know why the trope of cats killing HP still exists. The Honda f20 from the s2000 made ~250hp out of 2 liters with full emissions equipment. A first gen mustang made like 220 with no emissions to be heard of at more than twice the displacement.

We have come so far in engine design and thermal efficiency that any limitation the cat had has long since been overcome.

The big change in downpipes is the bell mouth design and the efficiency of that exhaust flow. In an equivalent catless and catted downpipe there is no extra power or flow to be had and that's verifiable on a dyno.
 

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The intake thing is probably arrogance. I know a couple of people who refuse to take in any new information because they have "worked on all sorts of cars for years".

Exhaust is plain weird. Half the drivers on road today were kids when catalysts stopped being a restriction.
 

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Discussion Starter · #13 ·
I'm not surprised in the slightest. This is why I refuse to buy a used turbo Subaru...

You should remap the ECU if removing the catalyst internals. Saying "there isn't a CEL" isn't enough. You can completely blow a motor without a single CEL illuminating. That modification is also highly illegal on the street so if I were you, I'd keep quiet about it....
I monitor all gauges no fine knock it runs perfectly fine as is and has for years and it definitely spoils up way faster for whoever said it would cause the opposite that’s crazy
 

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I monitor all gauges no fine knock it runs perfectly fine as is and has for years and it definitely spoils up way faster for whoever said it would cause the opposite that’s crazy
It doesn't. At all. Your exhaust would be moving too slow because of the expansion. Then bottle neck of recollapsing into the small diameter exhaust.

You think it does. In absolute fact it does not.

You do you. We will be here when "this piece of shit Subaru junk engine" burns down and it's totally poor engineering and not your decisions and you need help or suggestions.
 
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