effnay

Hello again all, got a couple ????'s about deleting the cat on my kids 95 Z28. If you guys don't mind throwing me a bit of info/thoughts on it that would be awesome.

1. Will deleting the catalytic converter affect backpressure, pcm or the likes? Just don't want a engine light staying on because of this. Just curious because there is no o2 sensor after the cat so would it make the car run worse? I'm sure there won't be a significant benefit or anything just want to ask before just cutting the thing out. The flange holding it is kinda rusted though so trying to be pre-emptive before it falls off anyway.

2. Kids asking me if the car will sound better or worse without it, I have no idea so I figured I'd ask.

3. Fuel mileage, any worse or no.

If you got any thoughts or whatever it would be great.

Thanks in advance

Injuneer

No codes in OBD-1 from removing the cat. Anyone with a sensitive nose and basic mechanical knowledge driving behind you will be able to tell the cat has been deleted.

No need for a tune, any increased air flow into the engine will be picked up by the MAF sensor.

Might sound very slightly louder, probably not much.

Not much in the way of power improvement, unless it was seriously plugged up. Way back in the day, Lingenfelter was building 383ci, 400 HP, street legal LT1’s. He said even at that HP level the cat resulted in less than 5 HP loss.

Will not materially affect gas mileage.

effnay

Injuneer, thanks for the reply. Can't tell you how much you're knowledge has been helpful getting this car to where its at.

Cheers

Injuneer

Thanks for the positive feedback. I just had a long time member tell me I'm a poor administrator.



Don't you just love it when they cloak their hatred in a false shroud of Godliness.

effnay

Lol, man. I don't think you could have put it any better on the godliness quote! Thats rings so true in so many ways. I've read so many threads on here where you try to help someone and they just don't take you're advice, it boggles my mind.

Cheers

Serenade251

Not sure if you already did this, I have had a 95 Z28 for quite awhile now. I deleted the cats and am running 3 inch Borla straight pipes. The car is LOUD. MY wife calls it the most obnoxious vehicle she's ever heard (but it carried us to our dates, so, not that bad I guess). However, I gained a few rwHP out of it and when coming down from 6K RPM the car now spits flames out the back. So, to a kid (or any man, really) it's pretty fun. I had no code issues, no real change in fuel mileage.

Noah217

Hey! bout deleting the cat on your 95 Z28, it does affect backpressure but it’s not too dramatic. Usually, there won’t be PCM issues, but it’s smart to invest in an O2 simulator to avoid that pesky check engine light. As for sound the car will definitely sound better getting a more aggressive tone.Just keep in mind it might affect fuel mileage – it shouldn’t get worse, but it really depends on your driving style. In short do it wisely and prepare for a better sound but remember, you might lose some efficiency if the car is driven hard. Let us know how it goes!

Injuneer

Makes no sense at all for a 1995. It's a single cat OBD-1 car (unless it was a California Emissions 4L60E car). There is no after cat O2 sensor, so there's no need for an O2 simulator. And the impact on fuel mileage and "back pressure" will be negligible.

I notice your IP address is from Poland. Maybe that would explain a misunderstanding of US OBD requirements. But wait, in your profile you entered "UY" for Uruguay. Might want to clear that up, or your account will be deleted.

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