Hi all,
First of all, I hope you are all safe.
I have a question regarding having a free flow exhaust and headers installed on our GSF cars, which both are cat less.
If I need my car to pass emission tests when I renew my car's registration, but because of the setup, I'm afraid that if I go with this setup it will definitely not pass the emission test in the country I live in, though it is not as harsh as the States, but still will require emissions to be tested, and the car has to pass it for the car registration to be renewed. If I install high flow cats such as GESI, Kooks or Magnaflow will this fix the emission problem? and how much horsepower the car will loose if the headers and the free flow exhaust make around 30-50 HP? I read that there is no such thing as high flow cats too, is this true and are they only a marketing gimmick?
My other option is to install the system and then reinstall the OEM parts when it comes time for the emission test/renew the car registration, but if I install headers (I already have a free flow exhaust system), I do not want to go to that route if possible, and I want to avoid taking the car to mechanics and reinstall OEM parts and then back to my setup. The car is my daily driver and not a track car.
I did read some of the threads, but still I was not sure.
Your help and experience in this regard is very much appreciated.
Thanks.
Regards,
Wissam

We don't know what levels of emissions your government requires to pass. That makes it impossible to answer that part of you question. Contact the manufacturer of these cats to see the specs they claim. It'll be more accurate than any guesses you receive here. Best of luck trying to beat the emissions test.

Thanks swfla, I believe any cats will do where I live, but I'm worried more about losing much power, and then it will defeat the purpose of installing headers on the car, and thus I was thinking about installing high flow cats too, but wanted to know if they differ from normal cats, and will the power loss be less between the normal cats and high flow cats?

Mfg specs are more accurate than anyone here can guess. Each mfg is different so no one can give you an accurate answer without accurate product info. If you want inaccurate guesses, I'm sure you'll get some from someone.

When I spoke to Paul at PPE he said the high flo cats that are an option with the PPE mid-pipe will cost you around 4WHP on a GS-F. That is it. So with that said, I'd get the mid-pipe that has high flow cats as an option, which I believe is only the PPE, unless you have someone add them to your current exhaust/mid-pipe.

Steve

Wow, someone who actually has mfg info. Glad I was wrong.

That's great Steve, thanks for the info.

PPE carries both the MagnaFlow Catalytic converters along with GESI cats. The GESIs are a lot more expensive, but you'll want to choose those:

https://www.clublexus.com/forums/is-...w-no-more.html

Lou

Good call. I just emailed Paul and let him know I wanted to upgrade to the GESI units.

Steve

Thanks Lou, I was thinking about the GESI cats, once I have the headers and fail the emission test ;-), otherwise I might go cat less when I install headers. I think GESI are the correct option to go with.

GESi bricks are made for racing series where catalytic converters are required. Yes, they do exist. If you do your homework you'll likely end up with GESi units. That's what's on my shopping list right now to go with the headers I need for the IS F. The GS F will remain factory. The wife wouldn't appreciate any more power than the factory provided.