Are high flow downpipes illegal?

Emissions Testing A catless downpipe is technically illegal as it violated emissions laws. With high-flow options, you will pass emissions testing and are in compliance with the law.

How much HP does a high flow downpipe add?

The amount of horsepower you will get from a high flow catalytic converter depends on your engine and the modifications you have made to it. You may see a horsepower gain of as little as 5 hp or as much as 60 hp. You may also get an extra 5-60 ft lbs of torque.

Why is a downpipe illegal?

Catless downpipe is not legal in every state of the US (almost in the majority of countries, I would say). Catless downpipe is illegal to drive on the street because of high emission concerns. If you are planning to install a downpipe for your daily driver, then you should look for a catted downpipe instead.

Will a downpipe pass smog?

Registered. Generally, an aftermarket downpipe will not pass a visual inspection at the smog shop.

Will a high flow Catted downpipe pass emissions?

You should be fine. Even if you go catless you will be ok. If you have MHD it will suppress codes i.e not check engine light. You will need to do a drive cycle.

Do you need a tune for high flow cats?

No high flow cats do not require a tune. As you are well aware, they will be optimized with a tune.

Are aftermarket downpipes illegal?

Is it now illegal to install an aftermarket exhaust system on my vehicle? The sale and installation of an aftermarket exhaust system remains legal in California so long as it does not exceed a sound level of 95-decibels when tested under SAE J1492 and complies with all other exhaust and safety laws and regulations.

Is Catless downpipe bad for engine?

Aside from not making any additional power over a high flow catted downpipe, a catless downpipe is bad for the environment and can also be bad for you, your community, and your engine.

Can I run a downpipe without a tune?

Downpipe does not require tuning to work. If you really don’t want a tune or you can’t afford it – you can install downpipe without a tune. The main reasons why I recommend you tune after installing a downpipe are horsepower and check engine light.

Does a downpipe increase sound?

Aftermarket downpipe definitely makes a car louder and sound more aggressive. This is because aftermarket downpipes are louder than stock and they reduce the backpressure in exhaust. Allowing sound waves to travel smoothly without collision.