Oregonjbird

Hey Everyone,

I was wanting to upgrade to a HFC and Intake. The HFC was for a slight increase in sound, and I figured the additional flow wouldn't hurt. If I wanted to grab a standalone later on I'd have it too. I also purchased a Takeda aFe Intake for MY 04. However, the more I read the more I am discovering I may be setting myself up to run lean. I know I could probably get away with doing one mod for sure and being safe, but do you guys think the 04 stock ECU can handle both without running lean? I liked the stock intake but I recently installed a Koyo all alum rad. The new all alum rad was raising my intake temps from the air being drawn past the top. The OEM plastic design was great at not conducting the heat.
I know the best course of action would be to buy a wideband or go to a Dyno shop and get sniffed. However I figured I'd see what you guys thought too.

spaded.racer

Should be fine. Maybe swap spark plugs when you do it and pull them after a few weeks to see if you notice anything.

noodels

Glad I installed plx wideband, maybe its the cost of a sniff test

sssmokin

So what was the verdict on this? I want to install similar mods. Did you have to get a tune? What exactly does the plx wideband do?

spaded.racer

A FlashPro is probably the best mod other than tires for an 06+ S2000, just spend the extra to get a proper tune.

Chuck S

I suspect the 2004 OE ECU can handle small changes like intake and a high flow cat. Won't hurt to check but we're not awash with engine problems caused by these common backyard mods. Not much you can to with the pre-2006 cars regarding tuning without an aftermarket ECU.

The '06 and later cars can be FlashPro tuned for significant increased mid range power by lowering the VTEC to 3600 rpm and tuning. Requires a high-flow cat.

-- Chuck

Oregonjbird

I ended up installing the intake and not the cat. I researched as much as I could and found some a Dyno chart or two of a 04/05 with same setup (intake and exhaust/cat). They had aftermarket exhaust too, but there was lean afrs in some of the RPM range. Most of it was fine, but this was a common message on s2ki too with the 04/05. From the sounds of it, 00-03 are the best years pre-06 because they run richer and can he leaned out with breathing mods that add some minor hp/tq gains from the stock ECU.The 04/05 is suspect as I mentioned due to Honda running a leaning fuel program on these ecus. So I chose to keep the stock cat with OEM ECU, but maybe I'm being paranoid.

Chuck S

I know the DBW cars run lean and a "thousandth over" is recommended for the exhaust valve clearance (0.012") to help prevent burning them. Won't hurt any version. Set valve clearance to max value for reliability as they tighten in use. We did a valve adjustment on an '02 car last month. Never been touched and all valves were in spec at ~175,000 mile. Fine tuned 3 or 4 to max clearance.

Hondata ECU will allow tuning the pre-'06 cars. Lots of money. Little benefit unless you can lower VTEC.

-- Chuck

Oregonjbird

DBW S2000 can e-tune and adjust AFRs plug and play for under $700 on the stock ECU... Add a HFC like you mentioned and lower the VTEC and you got 220-230whp. However, this thread was more about 2004/05 specifically since there isn't much options for these years. I did a valve inspection and check on mine as well and it was within spec at 91k. I adjusted a few. I just wish the ECU had a wideband O2 on these 04/05's.