[BLK235iNJ]

Can someone please provide the CONs with putting a downpipe on the car? I'm thinking of getting a new catted dp and I'd like to understand what the risks are with doing so.

I am running Dinan but warranty will eventually run out with them too.

My mods so far are Stage 2 Dinan, CAI and Dinan "muffler".

thanks

[Liquidpaper]

Originally Posted by BLK235iNJ

Can someone please provide the CONs with putting a downpipe on the car? I'm thinking of getting a new catted dp and I'd like to understand what the risks are with doing so.

I am running Dinan but warranty will eventually run out with them too.

My mods so far are Stage 2 Dinan, CAI and Dinan "muffler".

thanks

There are a few downsides. First, it may (or may not) be illegal to mess with your catalytic converter, depending on your state. Also, depending on what your state does, you may not pass smog with an aftermarket cat.

Second, it will be noisier. Generally, a catted downpipe is quieter than a cat-bypass pipe. However, people tend to like the noise (most of the time), and I don't find that it causes any drone on the highway (I have a catted downpipe).

Third, if you get a cat-bypass pipe, your exhaust will smell (faintly) of fuel. Without the catalytic converter, the exhaust doesn't get that "after-burn" in which the fuel smell is stripped out of your exhaust. It bothers some people, but not everyone. It's usually not a big deal.

Fourth, it is possible that your aftermarket cat will fail at some point in the future and cause a check engine light -- a cat-bypass pipe will always throw a check engine light (Code P420, unless you can code out the light with a JB4 or a tune). I know that it is better to get a higher quality cat than a cheap one (lasts longer, does a better job of scrubbing emissions, etc.), but I don't know how long they last.

However, on the up side, it's really the only bottle-neck in our exhaust system. Getting a downpipe will yield you some significant horsepower and torque gains, as well as sharpen your throttle response, reduce some turbo lag, etc., all from reducing backpressure on the turbo. It's a noticeable difference, at least in my experience.

[BLK235iNJ]

Do i need any supporting mods if I go catted? I plugged in my obdII sensor in today and noticed the car runs pretty hot 221 at one point. Will this mod end up generating more heat?

Originally Posted by Liquidpaper

There are a few downsides. First, it may (or may not) be illegal to mess with your catalytic converter, depending on your state. Also, depending on what your state does, you may not pass smog with an aftermarket cat.

Second, it will be noisier. Generally, a catted downpipe is quieter than a cat-bypass pipe. However, people tend to like the noise (most of the time), and I don't find that it causes any drone on the highway (I have a catted downpipe).

Third, if you get a cat-bypass pipe, your exhaust will smell (faintly) of fuel. Without the catalytic converter, the exhaust doesn't get that "after-burn" in which the fuel smell is stripped out of your exhaust. It bothers some people, but not everyone. It's usually not a big deal.

Fourth, it is possible that your aftermarket cat will fail at some point in the future and cause a check engine light -- a cat-bypass pipe will always throw a check engine light (Code P420, unless you can code out the light with a JB4 or a tune). I know that it is better to get a higher quality cat than a cheap one (lasts longer, does a better job of scrubbing emissions, etc.), but I don't know how long they last.

However, on the up side, it's really the only bottle-neck in our exhaust system. Getting a downpipe will yield you some significant horsepower and torque gains, as well as sharpen your throttle response, reduce some turbo lag, etc., all from reducing backpressure on the turbo. It's a noticeable difference, at least in my experience.