I'm not exactly a car guy or know much about cars, but I would love to get some performance headers installed. The problem is that the headers that I found for my car state the following "Eliminates the factory catalytic converter".

So if there is no catalytic converter would this play out when I would need to bring my car for emission testing? I'm from Ontario, Canada so I got to abide by my province emission laws.

2 Answers 2


In most places which have emissions testing, not only is there a smog test (where they attach your car to a computer), there's also a visual test. The inspector views to see that all emissions equipment is in place. Without your cats in place, this is an automatic fail.

Also without your cats in place, assuming since you said catS this is an OBDII vehicle, your check engine light (CEL) will illuminate due to the downstream O2 sensors either being eliminated or not reading correctly due to the lack of cat function. This, too, is an automatic fail at most testing places.

There are ways around these issues. You can purchase a set of aftermarket high flow cats which you can place after the collectors. Contrary to popular belief, cats don't restrict your exhaust flow unless clogged. This would require some exhaust work, but you're going to have to do this anyway. If Canada is anything like California in how they deal with emissions, this may be harder than it seems, though. You will want to check with the local laws to ensure you are doing the right thing before you waste a lot of money and time just to figure out it's still against the law.

Even with cats at the end of your headers, they won't be as efficient as they are on your stock system, mainly because they sit farther down the exhaust stream, which gives the exhaust time to cool. This makes the cats not heat up as well which is a key ingredient in how they work.

An alternative is to get shorty headers which will mate up to your stock exhaust. They basically replace the manifolds which come stock with tubular headers. While these won't provide as much of a performance boost, they do provide some and will still allow you to maintain your stock exhaust from the headers back. It's a fairly good trade off in the long run.


Yeah. With out other illegal cheats you won't pass a real emissions test. There are sensors in your exhaust system that provide feedback to the engine computer. With out your catalytic bricks in place to aid in burning off unburned fuels you won't pass emissions.

There are folks who cheat the system but you don't want to cheat, get caught, or provide bad emissions to the air all of us breath.

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