badass1g

Super easy to remove the factory mid pipe it took seriously 30 mins. Then came the hard part, the cats are VERY strong inside, it wasn’t like the older cars i have experienced where they easily come apart. Took prob 2 hrs or more to air hammer the junk outta there. If i had to do this again I’d def just order a corsa mid pipe. The sound BARELY got louder i would say 5% louder. I’m supercharged 600+ hp so I’d say that it did pick up a little power on the *** dyno. But def would not go this route next time. Spend the money and get the upgraded midpipe. 👍

MarkRacerX

Borla catless X pipe at $461shpd is calling me now!

Thanks for sharing!

badass1g

Yes! That’s what I did on my last c7 and i would go that route for sure if was going to do it again.

badass1g

Also Borla is what I meant to say not corsa.

sales @ WXM

Thanks for the share.

A client of ours bought a C7 with ARH catted LT's already on the car. We did heads/cam on it, while the headers were off he asked us to gut the cats. The tech came into my office and said its going take forever to clear out. Naturally I told him "let me show you a trick" then went back, beveled the edge on a scrap piece of roll cage tubing, confidently grabbed a 6 pound hammer. After hitting it a couple times, expecting immediate results. Me: "Yep. You're right it is going to take forever."
It is unbelievable how hard that material is now compared to when I was a teenager.

NSC5

Some of the 1970s models were the easiest cats to disable. My father stopped at an IH dealer in Colorado during vacation in 1979 because the new Scout wasn't behaving well in the mountains. The shop checked a few things and then asked if his home state of Mississippi did emissions testing, the answer was no. The tech then put the Scout on a lift, popped a cover off the bottom of the converter, revved the engine a couple of times causing all of the ceramic beads that made up the vintage cat to blow out on the floor, and replaced the cover. No banging or smashing of cat substrate required

Track

My last car had gutted cats. I could never get it through the Texas emissions tests. I would have to show receipts for $600 in emissions work and then apply for a waiver...every year. On the first fail every year they would strip off the inspection sticker. One year a cop ticketed me for no inspection sticker...refused to accept my explaination. I went to court to fight it, but the waiver from TXDOT was photocopied so many times the judge thought I was trying to pull something over on him. I even requested he send the bailiff to go to the parking lot to verify the new sticker...”Son, I don’t have time for that”. Bam...$250 more that year!!

Long story. The bottom line, WTH would you want to remove the cats from a 650hp car that passes emissions. Do you think an extra 5 hp or so out of 650 is worth it?

Kracka

I pass TX emissions at the dealership with no problem what so ever with the secondary cats gone (Borla X-pipe).

Track

I have no doubt a new car does...mine did for many years. As it wears, it eventually will not. Also, you are very lucky the dealer does not comply with the law and run a visual check for all emissions components installed and not bypassed. How much more torque/power does the bypass pipe give you?

Kracka

Secondary cats are un-monitored.

badass1g

Track lol. I dunno how your car wouldn’t pass emissions with second cats deleted. There are no obd engine lights for second cats. This will have zero problem passing emissions now, and forever.

Avanti

If it (emission inspection) is at a locale where ALL the paraphernalia must be in place to pass inspection, nothing else would matter; if a set of cats were missing--it would fail, pure and simple.

6Speeder

Legally, you're right. Realistically, wrong. He's talking about GUTTING the rear cats, not removing them. With gutted rears he will pass the sniffer and will not set off the CEL as it doesn't check the rears, only the fronts. And because the shells of the rears are there, he will pass visual. Ask me how I know.: thumbs:

OP: You're right. Sound change was negligible. Bummer.

'Merica

Shop around, I got mine for $393 shipped. A vendor here, Maryland Speed, offered it a couple dollars cheaper, but when I called their sales guy was an *******, so I ordered it through AutoAnything. It was to me in a couple days. Sounds great too!

KenBrownfield

I did the Borla Midpipe..... sounds like I am glad I did! Good info.

C7/Z06 Man

Do you know if you gained any HP or TQ gutting the rear cats? If so how much, or was it a wash, etc. compared to un-gutted?

From what little I Know on a 'stocker' gutted rears maybe a wash or less.

Pics from my file:











Nice job, 100% gutted but it looks like a lot of work. From the looks of the factory 'X-PIPE' itself it looks to be a very good design if not the best.