Horsepower gain in just removing cats?

[95Viper]

What gain in horsepower could you expect in just removing cats from a gen1 side exhaust and leaving everything else stock, even stock muffler? How about sound?

 

[BigCarrot]

You'll gain a few, but another great thing about it is the wieght reduction. Those things are heavy!

 

[Chuck 98 RT/10]

And heat reduction.

 

[Anthony - 98 GTS]

Sound should be louder and deeper.

I would guess a 10 hp gain.

 

[Moundir]

Is it true you lose tq cause you need some back pressure especially with headers?? Also is it a must to get the vec1 when taking out the cats? Thanx.

 

[treynor]

VEC-1 won't help you much when you remove cats - the rear O2s notice the missing cat and set a "check engine" code. And you definitely don't lose torque with headers & no cats.

That said, why not get a pair of high-flows? You will avoid the fault code and attendant loss of power, you'll avoid the nasty gas smell, and you'll lose -maybe- 1-3 HP over what you would see with no cats. I'm running high-flows in my 996 RWHP DLM car, so they flow enough for a stock application

 

[STOUT 1]

There is no rear O2 sensors on a 95.

 

[ElDiablo Viper]

I gained 7RWHP and 13RWTQ after taking the cats out and installing the sims.

 

[95Viper]

I'm told this is true, Vipers need a little backpressure or they will lose horsepower.

The problem is to understand how much pressure. I can never find this out. Stock has too much pressure and open headers (like dumps) is too much(I'm told).