Okay, been having issues with an Evo7 tripping off the CEL due to O2 sensor failure and no catcon readiness.

Finally been able to get into the ECU to try to play with the settings.

Here's what's in the car: fic 750 cc injectors, HKS 272/272 cams.. fuel pump with fuel pressure regulator at approx 37psi idle. Full Fujitsubo exhaust with a high flow cat. Rear O2 sensor is hanging outside the exhaust right now.

First thing's first.. STFT is pegged at 150%, can't seem to do a thing to change it.

O2 sensor is indeed cycling and working.

I have the injectors scaled down to 665 and have changed the injector battery voltage to 0.552 at 14v right now... *just* to get the O2 feedback to be between 100-130% correction. The STFT still seems to not change at all, the LTFT is at 128 (before it was pegged at 150 as well).


I'm a little confused as to what's causing this issue. First of all, I tried to decrease the injector scaling so that the injectors would dump more fuel.. sure it does, but STFT still stays pegged.

Then I decided that maybe the battery voltage needed to go up. No dice, the stft stays pegged. Now surely I can get the O2 to read more rich as the battery voltage goes up.. also when I decrease the scaling. What's wrong with the STFT!

Just trying to get a map together to try to help out this car. It idles a little smoother now that the O2 feedback trim is close to 100% and O2 still cycling. I've changed almost all my parameters to match my own car running helix 272's ........ but I'm on the stock 550cc injectors.

Where should I start next with the STFT? I'm suspecting because this stays pegged it's probably not helping with the CEL going off.

On a side note, on cruise the O2 seems to cycle fine, at WOT the o2 does stay at a nice steady 0.92 volts and we've settled upon this since it gives almost zero knock on a quick pull through 1st to 2nd gear.


On a side note: Stupid ECUflash/tactrix drivers I cannot get it to install the VDP com port to work on this laptop here. On a newer laptop it shows up fine (So I can use the scan tech to verify the CEL codes). Is there a way to force the VDP drivers to go along with the openport tactrix cable? I've uninstalled/deleted/reinstalled with the newest version of ECUflash and obviously it works on the newer laptop, but not mine.

Thanks for all the help!

 

Why is the rear o2 not in the car?

Put it back in and see if it cycles. It will not cycle as much as the front, but this could be why it is not going ready.

What is the base fuel pressure with the vacuum hose disconnected?

 

Dennis,

Matt suggested I try to remove the rear O2 to see if the Cat would come ready in case it was the problem.

The rear O2 still cycles a little bit on it's own. I think the base pressure was 42 when it was disconnected, and drops to 37ish with the vacuum hose on.

 

I ran the scanteck OBDII to do more testing.

The O2 voltage readiness didn't pass as well as the Catalytic converter readiness.

There was a CEL for P0000 which doesn't list as anything, and a P0170 which is O2 b1s1 no voltage.. ie the front O2 sensor was dead.

With the new adjustments to the flash, the Front O2 still works, the Scantech sees it cycling.

The weird thing is that the STFT is at 7% which is more than reasonable for me, but Evoscan shows it at 150%.

 

Is this a JDM 7? It's the first time I've heard of a 7 with a rear O2. What is the ROM ID? Do I take it your tuning of the front O2, I have found this to be a really inaccurate method.

MB

 

I don't have access to a wideband, so tuning the front O2 is the best bet in terms of getting the ecu in check.

This is an Evo7 that's LHD which I know there are a bunch floating around.

The rom ID I'm using is:99860002