So I was thinking of my next project, exhaust, and before I go spending cash, I'd like to hear facts.

My plan is this.

Install my PLM header, after the header I fab up an electric cutout, after that my stock cat and then stock catback.

So on days where I want to hear nothing I leave the cut out closed. Then on days I want to hear some noise I flip a switch and it's just headers to open pipe. After the cutout would be another flange and some piping to get the exhaust away from my passenger.

I know this is physically possible, but is it safe. I don't mean for my ears but for my car.
I have heard people say just headers and no backpressure will run the motor and others say it won't be a problem.

Facts?

Also, if back pressure is an issue, could I extend the piping after the cutout to create back pressure? Or would it need a resonator?

Thanks guys

 

Backpressure is not an issue. Run the cutout and you will be fine.

 

Everything after the collector is a restriction. Unless the header was poorly designed.

 

That being the case. If I were to drive the car with just header and cutout by passing the cat and o2 sensor...do you think I would through a code?

 

Yes. Unless you run a full EMS that disables secondary O2.

 

So when it comes time for inspection I can always close the cut out but if I'm throughout a code, will that effect the performance?

 

Correct.

 

And if I don't will that ever t the cars performance?
I don't mind seeing a light every now and then

 

I don't think the secondary O2 will limp it; the primary will though. (99% sure )

 

If it doesn't effect performance then that's what I'll do.
If it does then I could always put the cutout AFTER the cat... Rather not though