Hey guys, I recently acquired an 07 S2000, and it came with a brand new, never installed Hondata FlashPro. The car has never been tuned, but it does have some simple bolt ons: an OEM intake box mod, a Berk high-flow cat, and a Tanabe Medallion exhaust. That said, the car had a CEL for P0420, so I installed 2 defoulers, and sure enough, it went away. This worked in the past with a couple of my other S2Ks so nothing out of the ordinary. Recently, I got a P0139 code (O2 Sensor Circuit Slow Response (Bank 1, Sensor 2) for the S so I did some digging and found that 06+ O2 sensors are known to be very sensitive. I read that Hondata FlashPro can disable the downstream O2 sensor entirely to prevent the CEL from popping up.

I downloaded the Flashpro manager software (4.3.0) onto my laptop and started looking into it. However, under "New Config" while hovering over the preload maps, I don't see the "S2000 2006+ stock equivalent" tune function as shown in the LHT Performance YouTube video where he was going over different sets of preloaded tunes. Instead, I only see the "S2000-US-2-Tuned Injector (310) - US/Canada S2000 2006+ 'Tuned'" and the CARB version of that (along with other options with various mods that I'm not covering here). I simply want to remove the P0139 CEL from the Berk HFC pipe and am not particularly interested in increasing power. With that in mind, would I be okay using the FlashPro S2000-US-2-Tuned map with my current mods to turn off the secondary O2 sensor?

I occasionally like to do spirited drives down mountain passes (ex. Tail of the dragon) and some back roads, but not at the cost of causing harm at the same time. I'm not a hardcore track junkie, so there's no need to go aggressive or try to squeeze all the power out of a 2.2L. I'm sure there will be posts suggesting I 'get an e-tuner,' but as I said, my main goal is to clear the P0139 CEL and keep it off. I've researched all the S2K groups and archived posts here, but I can't seem to find the answer I'm looking for regarding the standard preload 'tuned' map and it's impact on the car. Would be awesome if someone here could provide me with greater clarity and assurance on this. As of right now, it is still stock.

 

I have a 2006 FlashPro tuned car and have never had a CEL nor failed a OBD2 port smog check in the 10 years this tune has been running. Running a very similar intake and identical cat and exhaust to your 2007. I'm thinking there should be a check box to enable or disable the secondary exhaust sensor and prevent setting the CEL and I assume it's been done on my car but darned if I can find it looking thru the FlashPro calibration and not really knowing what I'm looking for. Never had a CEL in the year of so before tuning with the same intake and exhaust.

You've been here to have read all the "de-fouler" posts for eliminating the CEL. Tried any of them? $600 or $700 to simply eliminate the CEL light with software vs maybe a $50 hardware de-fouler?

If anyone knows where or if this is in the tables let us know.

-- Chuck

 

Yeah, I have two defoulers on it right now, and it worked perfectly to clear the P0420 code. However, another code, P0139, pops up with the two defoulers on. In the past, I had a couple of S2Ks and had no issues addressing the CEL from a decat, but to be fair, they were all 1999-2005 drive by cable cars, not drive by wire. This is technically the first drive by wire car that I’ve put decat & defoulers on, so this is definitely a surprise.

I thought about widening the hole in the defouler by 1-2mm, not too much, just enough to allow a little more gas to flow through. That being said, I received an email back from Hondata last night regarding my missing "stock equivalent" tune file, and they’re going to help me with that to get me rolling. My state doesn't care about emissions, so I'm not worried about smog tests, but for future reference, I’d like to know if anyone has an alternative fix that worked for them to address the P0139 code on 2006+ DBW cars.

These forums have a wealth of information archived through searches and back threads, but I'm hoping to find more relevant info than skimming through a bunch of old 10-15 year old threads.

 

To put the factory tune on the car see post #9 in this thread. You're the other FlashPro question I referred to.

-- Chuck

 

This is great info, totally missed this recent post yesterday. Thanks!

 

FYI, the big gains available with a FP tune have very little to do with squeezing more hp out, but rather improving area under curve. Midrange.

This is accomplished by lowering vtec rpm. This only works if you have a tp or hfc (otherwise you actually lose power lowering vtec).

Vtec will still only engage if you're in upper throttle range, so its not like you'll be in vtec just cruising the hwy.

This not only gives you real midrange power gain, it effectively increases power band so don't have to work so hard to stay in vtec between shifts when accelerating hard.

You can likewise increase redline to around 8350 rpm, and still have lower piston speed than ap1 at redline. Which increases powerband on other end.

 

Would an FP novice user, who doesn't want to tinker with the A/F ratio and other calibrations, simply lower the VTEC engagement point to 5600 and raise the redline to 8300-8400 for modest gains? I was able to get the 'stock equivalent' tune map and disable the secondary O2 sensor to prevent the CEL, thanks to Hondata.

 

Please share the Hondata furnished procedure to disable the secondary O2 sensor to prevent the CEL.

I doubt you'll notice a 5600 VTEC since OEM is 6000 and 200 more revs on the limiter won't make any difference either. Still have to rev the tits off it for any power, just as Mother Honda intended to get a that noticeable VTEC Yo! feel at 6000rpm. You need to look at the fuel tables to do anything. This is why my car was road tuned by Gernby 10 years ago. Didn't happen overnight. Lots of diagnostic tunes loaded into the ECU one at a time (including one nicknamed Prius Towing a Trailer that takes forever to get to 8000rpm at WOT), data captured, sent to him, and adjustments made, new calibrations sent back. Rinse and repeat. If 5600 was a typo and you meant 3600 then you gotta do more than tinker with the fuel tables.

-- Chuck