HI all~! As you might all know, I drive a Honda Fit AT. I recently did some work on my inatke / exhast system and now I am a little confused.

Here's what I did so far:
T1R CAT-BACK
T1R CATALYSE
T1R CARBON FIBER INTAKE

The confusion all started when I talked to a few buddies of mine. I told them that I changed the Catalyse of my car and I aint sure if its really helping my car when I accelerate at REd Light ( I do city driving 80% of the time)

Here's what I get:
1) Catalyse is ONLY GOOD if you do a lot of high speed driving - such as cruising on highways. Its not good for City Driving cos I lose power at low RPM

2) Catalyse waste a lot of gas cos I lose all the back pressure, which means I need a lot of gas to accelerate.

Given such feedback, would you guys suggest I switch back to factory Catalyse... or keep the current makeup? Noise is also an issue....

I am SOO confuse... I am new to this whole Honda Car Modding thing (I used to drive a "Toy" car)

ANy recommendation will be nice

PS - I am planning to change headers as well. Turbo In teh fture maybe

 

IIRC, the fit needs some back pressure to be most efficient. typically you may see a resonator after the catalyst, so without the resonator, you may be hurting performance.

you replaced, or removed the catalyst?

typically a high-flow (aftermarket) cat will lower back pressure, and without a high output motor, this too may affect performance. if the catalyst is its own section, just try replacing the stocker and see what happens.

just because they make a part for your car doesn't always mean it will help or improve it (like a blow-off valve)

best of luck

 

Well, by law, if you want to go through aircare (in 7 years) and want insurance, you MUST have a catalyst. You canget a high flow cat that will increase flow. If you T1R one is a high flow cat, then keep it. With the aftermarket cat, make sure that the car still goes into "Closed-loop" operation. If it doesn't soem other things may go funny. IE: check engine lights will not be operational, fuel economy will drop, and so on.

 

Ummm..I should sit down and chat with my buddies and find out whats been installed... I like performance, but I need to knwo what things are for.. I don't want to BLINDLY get parts without knowing what is needed.

Thankls for all the help guys.

BTW, My cat needs a O2 by-pass.. does that mean its not in a close loop, thus is actually bad for my car?? @.@

 

by-passed O2 sensor means you're not running one, or both of the O2 sensors needed for the OBDII emission system. So depends on how it was "by-passed" you may encounter a check engine light, and/or fail AirCare. (Is it 7 years now Toy Yoda? I thought it was 2 years for new cars?) Anyways, this is all the same regardless of make (Honda, Toyota, whatever).

Decreasing back pressure by going to a higher flow cat might help performence some mostly because your engine will be able to rev up the rpms more freely. It really doesn't have anything to do with actual vehicle speed.

 

[quote=j5ive] So depends on how it was "by-passed" you may encounter a check engine light, and/or fail AirCare. (Is it 7 years now Toy Yoda? I thought it was 2 years for new cars?) Anyways, this is all the same regardless of make (Honda, Toyota, whatever).
quote]

From what i can remember, a noew car (2006 and newer) is now equipped with CAN data NOT OBD II therefore, aircare is 7 years.

 

Don't mean to be disrespectful but what are you trying to accomplish with your mods? The most enlightening day came for me when a member of this forum asked the same question of me.

What I mean is that in stock form you had one of the best handling fuel efficient cars in the world.

As for the catalytic converter please take a look at the following article. It's what Honda had in mind when they designed the L-Series engine (which includes the cat).

http://asia.vtec.net/Series/FitJazz/lseries/

I hope the above helps you to resolve or confirm the direction you are modifying your Fit.

 

i felt power gains off the bat with the T1R test pipe, especially during nitrous runs.

 

Are you running a spark plug non fouler 805FitSport?

When I get my header and header-back exhaust thats what Im going to run. Non fouler drilled out so the CEL doesnt come on. I put one in my friends MazdaSpeed Protege, also in his 3 Evo8's, my friends 05 RSX-S, and an SRT-4. Theyre all still running them with no problems. 2-3years running.

 

Ok, so today at work I gutted my cat. The only thing I really noticed is a difference in tone. It got a little deeper, basically more aggressive. No buzz at all.

Im running an Aspec CAI, OEM exhaust system, and header with a Netami TwinLoop muffler.
First off, I noticed a big difference with the Netami muffler and running no muffler. When I installed the muffler the car drives so much better. More power up top and mid range.

Gutting the cat didnt do anything as far as my butt dyno feels. Maybe its broken?
I need to add the plug defouler, I havent got a CEL yet though. Only takes a few miles. It'll pop up.

 

this plug defouler is like this thing right?

eBay Motors: O2 Sensor Simulator MIL CEL Eliminator Fix 02 Sim (item 280064725077 end time Jan-06-07 23:15:00 PST)

how does it work?

 

I would like to gut my cat too, but here in Las Vegas, we have those roadside sniffers, they take your picture, and you get a warning in the mail, 3 strikes and your out!
Then you have to take to a mandatory smog check!!!

 

Yes, its basically like that. You can buy them at an autoparts store for the same price but you'll get 2.

CEL came on last night.

DAMN!! Thats almost scary...
I noticed a difference in smell big time. I think its the interior particles cleaning out. My Mx6 hasnt had a cat in years and Ive never noticed that smell. Takes some getting use too.