so is a tune required if you just bolt on an exhaust? will it set off an CEL's?
adding an intake, would that require a tune too???

 

It's my understanding that some exhausts (mostly the 100 cell ones) can set off O2 warnings because they're more free-flowing. This is mostly harmless and a tune will only set those O2 limits higher.
A few of the higher end 100 cell exhausts (like the europipe, for example) have 2x the surface area and won't trigger CEL's.

 

The surface area of the Europipe 100 cell cats is almost equal to the surface area of the stock cats. Hence if you're worried about smog inspection but want 100 cell cats, Europipe seems like a good choice.

 

Unless you live in CA... Then it doesn't matter as no aftermarket exhaust is CARB certified so you'll need to put the stock one back on to get it smogged. That or grease the palms of the mechanic to skip the visual inspection...

 

I wouldn't worry about not passing smog with a Europipe. The exhaust is tucked up so tight and so well made it looks factory. I never had a problem with the smog inspection with mine.

 

I just passed with a Speedtech that doesn't look anywhere near stock. No grease involved. Just a good Vietnamese smog technician.

 

The sound from my catless EP2 Loud is more than enough to justify upgrading the exhaust for me. I'd have done it even if I didnt' get faster turbo spool or more horsepower, so those things are just bonuses .

 

I agree, while a change in peak HP might be harder to feel the difference of, I thought the throttle response and turbo spool (faster boost) was greatly improved after my exhaust upgrade.

 

Get the exaust and your car will spool faster and sounds eager

 

Same thing as my wife after she gets an LV bag.

Jim