elowderm

Hi, new '08 F owner in central Texas looking to get headers and JoeZ exhaust installed this year. Sorry if this question is redundant but I didn't find the answer in a thread. I want to install headers but still pass my emissions inspection. I know that adding the JoeZ exhaust will remove two of the four stock cats on the F, and as far as I can tell if I take off the stock headers it will remove the other two cats. The upgraded headers can come with or w/out cats.

My question is will only one cat on each side still pass the insp? Or for that matter will a high flow cat(one on each side) pass the insp? I'm assuming no cats will not pass insp at all. I appreciate any feedback, especially anyone that has first hand knowledge passing emissions with their F and has either of these headers installed here in Texas.

flowrider

iTrader: (9)

Search and you will find. This issue has been talked about many times. In a nutshell:

It is illegal to tamper with working stock cats - PERIOD! That means all four of them. With that being said, you will probably pass the sniffer with aftermarket High Flow cats, but you would never pass the visual, if the inspector knows or cares about what he/she is doing.

And, I happen to be a PPE owner with a modified exhaust and HiFlow cats.

Lou

elowderm

Thanks Lou. Im inbetween Sikky and PPE, is there any drone with the PPE and high flow cats? I bought mine with a muffler delete and the drone can get annoying.

flowrider

iTrader: (9)

^^^^IMHO, there will be drone with a third party exhaust. See these two threads.

https://www.clublexus.com/forums/is-...emissions.html

https://www.clublexus.com/forums/is-...z-exhuast.html

It appears drone is a personal experience. I have driven in an F, with stock headers and the JoeZ exhaust and the same F with PPE, no cats and the JoeZ. Both experiences had drone, again IMHO. Other members of this forum say otherwise. That's why I say it's a personal thing

My exhaust, IMHO, sounds great, produces power (though not as much as a catless JoeZ) and has absolutely no drone.

http://youtu.be/stqr-gE06TM

Lou

TXGS430

@sickpuppy Hey man I am currently running ppe catless headers to a full Joe Z catback and a titanium intake elbow with drop in high flow filter. I see you mentioned you are running welded in high flows .. What are your thoughts does it really tame the sound all that much. low key i love the way mine sounds but i would consider welding in high flow cats if it would clean up the engine note a little bit as well as give me a little bit more induction noise. Your feed back would be much much appreciated!

flowrider

iTrader: (9)

^^^^Can't really answer your question as I have never run without cats. IMHO, having catalytic converters in an exhaust system is the socially responsible thing to do.

ThisOldNSX

I live near Dallas. I recently got the RR Racing intake, tune and the PPE headers (stock exhaust). I am only running 2 of the 4 cats since the new headers don't have them. I just got the car inspected last week and it passed no problem. I am not certain, but if you do headers without a tune you will throw a code and probably not pass. The tune fixes this. I hope that answers your question.

xdejablu3x

I'm FBO + tuned and used to be stationed in Killeen. I have Magnaflow hi-flow cats that I purchased from RR Racing when I got my headers. I didn't want to smell exhaust fumes all the time. The cats help cut it down by like 70%-80%. I also replaced the pressure vents in the trunk as mine were dry rotted and the fumes were going into the cabin before. I think they are worth it. Now they sell the PPE headers with GESi cats welded to them.

MartinsISF

The high flow cats definitely made a noticeable difference in the sound for me. I had my PPE EL headers installed last year and ran without cats at first. Once my GESI cats (the cheaper version) were installed it really did clean up the sound quite a bit (less raspy and reduced drone a bit). I did it mostly for the smell, which it helped a lot, but the sound improvements were great as well - sounds more refined.

Also, as mentioned somewhere else, replacing those vent flaps in the trunk is highly recommended - I had mine done a few months later and it was a HUGE improvement!

Isfisaiah

Thinning of going fbo on my 2008 Lexus isf 55miles I daily this and every several months travel state to state which is 2k miles for me. Ppe UEL headers and I got boozka exhaust with no cats it’s the axle back. So I’m wondering if getting Ppe UEL headers with cats or no cats if it changes reliability, obviously I know it does not matter what but in general is what I mean. As well as i live in Texas as well so I know the tune should help also pass emmision. Hoping to get y’all’s feedback and advice thank you

xdejablu3x

Can you please not ask these same questions in old/existing threads? There are a plethora of information for well over a decade on this and other forums that have most definitely answered your questions. I suggest you yse the search function on this forum, other forums and even using other online search engines like Google to find a vast amount of information regarding the IS-F, the aftermarket support and enthusiasm/enthusiasts that surround it. Not trying to belittle you but you need to do some homework and learn about your IS-F. Even living in Texas, depending on your county, may have to do an emissions test and tunes don't always work.

Meraki Autoworks

iTrader: (8)

We would do PPE catted now, hot seller for us.

-Josh