Unfazed

Hello everyone my name is Alex i am 19 and from Newmarket Ontario. I recently purchased my first civic 2 days ago. It is a 1998 Honda Civic Si 2 Door Coupe. I believe the car has a B18-- motor and i believe he mentioned GSR might have been the tranny ( Will edit when i find out)... The car is boosted at 16 pounds with a Garret T3 turbo and a custom 3" exhaust which is straight pipe. It has a Hondata ecu chip and he said it was tuned for the track. It also has launch control at 6000rpm. The exhaust system is really loud on this car and where i live the authorities are very strict and people get nailed all the time. I asked him about the power the car makes and he said that it makes between 380-400 whp he will be giving me the dyno sheet and a couple more extra parts in a couple of days. I drive to college every day and i need my car to not attract every single cop on the road due to the sound. The main problem that I am trying to figure out is the exhaust and specifically the straight pipe he is running. The car will not pass the sniffer for sure and I am trying to figure out which catalytic converter i need to put on for it to be able to pass emissions testing. Here are some questions i have.

1) Best Catalytic Converter price/brand/quality wise i read negative on ceramic ones?

2) Any difference between a "High Flow" Cat and a normal one?

3) Will removing the straight pipe and putting the converter and a muffler reduce the "ridiculously loud" exhaust note?(Which i kinda like)

4) Will the car need to get re-tuned with the new cat and muffler in place? How much would i be looking at price wise for that to be done and any shops around where i am (trusted ones) that anyone could recommend?

5) Anything else i might need to change for it to pass?

I thank everyone who has some helpful advice for what i need to do as I need to get this car up and running since its been on my driveway 2 days looking at me while i take my other car to school. Thank you again.

LS97Civic

The difference between a high flow cat and a normal one is exactly what is says. A high flow is more open to allow more air to pass through. About your tuning question, that will depend on how the tuner did the tuning. If it was tuned using a sensor before the cat, it shouldn't need retuned.

Unfazed

I understand what you just explained to me LS97Civic but this only helped me with choosing a high flow cat instead of a normal one and that the car might not need a tune. I still need clarification on the exhaust note and if it will be "quieter" after removing the straight pipe and putting the cat and muffler. Also will i have any issues with passing emmisions with a car that has this much power? Also any recommended brand model and price on a good cat as i am not a pro and this is my first civic like i have mentioned. And lastly "if" it requires a re-tune what am i looking at price wise?

LS97Civic

I would think it would make it a little quieter, but it should still sound decent. As far as brand goes, I'm not sure so I don't want to give you a wrong answer. Just make sure you get something that matches the size of the downpipe and exhaust. The amount of power will not play a role in your emissions. However, the emissions laws in your area might prevent it from passing. I would look them up because they are different everywhere. As far as your tune question goes, I am unfamiliar with your area so I can't really give you an answer for that either. In my area a tune is generally $300-$500. But some places will go cheaper if its just a re-tune. See if you can find out where the guy had it tuned before, they will be familiar with the car and the tune set up.

apexi_rsx

I have a random technology hi flow cat on my turbo z6 and I have passed emissions year in and year out. Its best not to choke the turbo with a normal cat but it can be ran either way u may loose alil power with a normal cat. As for retune as long as ur not boosting more u should be fine. I've noticed with internal gated turbos they will tend to boost creep with a hiflow or test pipe in colder temps.

Unfazed

Alright thanks for the clarification guys. I will look into the random technology cat. It has a full 3 inch exhaust so does that cat come in that size or is it universal? Its getting an e test in a few days so i will let you know how everything goes. Noob question but what would "boost creep" be? Thanks again!

Arthas

Dont use a catalytic converter, use a resonator.



Done.

Libertariat

Disagree.

OP:

Get a vibrant 300 cell metal core race cat. You'll have plenty of flow and pollute a lot less. They're ~$100 and look/work great.

Don't be worried about power either, several of the dyno tests I've seen on dyno and N/A cars have shown to be minimal. Several tests even lost power on the bottom end when not using a cat.

canadaek

we have emmision testing and minstry of enviroment does spot checks

kyden

every turbo honda i've seen with a cat has had it fail shortly after usage. they just run too rich for the cat.

Libertariat

It's not a matter of rich, a tuned car shouldn't be running rich or lean. It's likely a matter of heat. Thats why race cats have metal cores.