djamps

iTrader: (1)

Exactly right

Don't mess with non foulers just disable the catalyst codes so you can retain your MPG's and off/part throttle tuning.

SparkleCityHop

iTrader: (30)

Awesome guys! This will also keep the CEL from coming on so that I can keep my eye out for codes that I really need to be worrying about! Yet another reason for me to buy the Osiris Tuner version.

Thanks!

djamps

iTrader: (1)

The catalyst inefficiency codes are harmless as long as you're running HFC or test pipes. It's the ECU saying 'hey, the stock cats aren't working right' but it still uses the lower o2 signals for self trimming -- other more serious codes will still pop up if there are other issues. By installing non foulers you hinder the ability for the ECU to properly adjust trims whether or not you're running osiris.

FYI you don't need the 'tuner' version to disable codes...your local authorized osiris tuner as well as uprev's e-tuning service can also disable catalyst codes.

SparkleCityHop

iTrader: (30)

Yeah, I'm not buying it just for the codes. I want to be able to tune as well. I figured that I can either:

A) Send my ECU off for a flash ~$300
- Lowest initial cost
- Advantages of the flash, but tune is not dialed in to my car

B) Pay an Osiris tuner $500-$900 to tune using their tuner cable & dyno
- Medium to High initial cost (depends on the shop)
- Probably the best quality initial tune
- I can't adjust/modify the tune as I make changes to the car
- I can't take the tune with me to a different tuner if I decide to switch
- I can't log with Cipher, etc

C) Buy Osiris Tuner version for $600(Marketplace)-$700(Retail) plus an e-tune $50
- Medium initial cost
- Gain advantages of flash and an e-tune based on data logged from my car
- Still not as good quality tune as a dyno tune
- If I have a shop dyno tune and use my cable, I can "take the tune with me"
- I can adjust/modify the tune as I make changes to the car
- I can log with Cipher, adjust maps myself, or buy extra e-tunes for $50 ea.
- I can learn about tuning and increase my knowledge and understanding of my car

I'm thinking that C is the best long-term option for me because it gives me the most flexibility.

Reidonly

I don't see how anti-foulers would have anything to do with your AFRs or fuel economy. I have had mine on with test pipes for the better part of a year and they have performed flawlessly. The FRONT bank of O2 sensors are what the ECU uses for tuning, the rear ones are just for emissions. I just got 24mpg on my last tank with mixed driving and rarely dip below 20-21mpg even beating on the car regularly.

djamps

iTrader: (1)

Well I have plenty of logs to prove otherwise and I wouldn't have started this thread if it wasn't so.

Do you have logs to show your A/F is always spot on during idle and cruise? I'd love to dig deeper to see if perhaps what I'm experiencing doesn't apply to all model years...but at this rate I don't think my 2004.5 is alone.

ImportPartsPro

iTrader: (512)

That is really funky. Goes against everything we have learned about 02 systems for OBDII cars. Usually Reidonly would be correct in that the rear 02's are there strictly to monitor catalyst efficiency and have no effect on fuel trim at all. It sure sounds that way though since you only had this issue at cruise where closed loop control is used.

Did anything else change when you pulled the non-foulers off? If this is the case, a lot of people with aftermarket HFC's or test pipes could be in trouble, yet I have not heard of anyone else having trouble with this. Hell, the Berk HFC's have the sensor bung extended out a couple inches and have a restrictor in them.

djamps

iTrader: (1)

The ECU is most definately trimming off both sets of sensors in closed loop. Especially idle and cruising. No changes in the boost areas with or without antifoulers; just closed loop.

Nothing else changed...just threw it on a lift and took them off then went for a drive.

Before I was seeing in the logs - target 14.7, actual 14.0, and at the same time, ECU _adding_ 15% fuel. So as you can see, the ECU was creating it's own rich condition at times. Not all the time, but a good 50% of the time.

After removal...everything spot on and no more A/F fluctuation, smoother and snappier throttle response; I'd venture to say it drives like a different car now at low loads.

djamps

iTrader: (1)

But how many N/A guys with TP's and HFC's actually monitor their A/F ratios and ECU logs? THey didn't cause any issues under heavier load where the butt dyno would notice.

And the issue will barely (if at all) show up on a dyno where you're putting heavy loads on it -- I only had this A/F instability on the highway and long stretches of road for the most part and only about 50% of the time, since it was a rich condition I never felt hesitations or anything while it was happening so without the ECU logs and WB I would have never known.

ImportPartsPro

iTrader: (512)

I had Berk HFC's on a supercharged 04 and didn't see any of this. Idle and cruise AFR's were spot on, without any over-correcting going on. Good news is that your problem seems to be fixed, bad news is that this raises more questions

djamps

iTrader: (1)

What ECU were you running? I would also imagine not all antifoulers would act the same, maybe yours were letting enough gasses to reach the sensors and mine weren't...or hell maybe yours restricted it so much the ECU didn't bother with trying to use them. Any CEL at the time?

ImportPartsPro

iTrader: (512)

Car was running a Procharger (yuck!) with an Emanage Ultimate. The sensor bungs on the Berk HFC are a couple inches off the pipe and the restrictor was really just a small hole drilled in the pipe going up to the sensor instead of the same size as the bung. No CEL or any trouble with fuel trims. Logged with a consult as well and compared readings with the primary 02's because we had major troubles with the clogged stock cats.

You're running UpRev right?

djamps

iTrader: (1)

Uprev indeed, no add-ons or electrical system mods at all for me.

The emanage ultimate is fairly advanced add-on; although I wouldn't be surprised if it passed closed loop triming functions to the stock ECU, I would still be interested in seeing logs from uprev or even 100% stock tune setups.

ImportPartsPro

iTrader: (512)

Yeah, can't even log fuel trims with the EU, but we had Consult handy so just ran with that. Reason I even went there is because the car originally had clogged cats and A/F went completely nuts under load.

djamps

iTrader: (1)

Not exactly a Nissan but more of a general OBDII statement that seems to confirm my experience (rich long term trims):

http://www.m5board.com/vbulletin/e39...ml#post1059009

0jiggy0

iTrader: (13)

I have to look into this. This goes against everything ive experienced in a decade of diagnostics. My own car and hundreds of other. Like said before glad you fixed your problem. But antifoulers and brillo definitely isn't affecting how my car is running. I dont know how to explain what is going on with your car.

djamps

iTrader: (1)

You won't see the it with normal diagnostics. You won't even see it on a dyno. Since I do all my own tuning on the street and I'm **** retentive with my A/F it became evident to me over a period of time and only under certain conditions.

My trims were decent at idle and during most of my driving. You'd have to be logging for at least 20-30 minutes before it even happens and even then you have to have the conditions just right like cruise control or a steady foot on the freeway.

Heck some people might not have even considered it a problem much less known it was happening unless they log A/F constantly... I'm just **** about it like that. I need 100% control over my tune and with antifoulers it simply isn't 100%.

djamps

iTrader: (1)

Also, I wasn't using brillo; I don't know if that makes a difference but certainly I wasn't throwing any codes.. Too many variables....

ImportPartsPro

iTrader: (512)

Are you using test pipes? Have you disabled the catalyst DTC ?

djamps

iTrader: (1)

I have 3" catted downpipes - same ones used as upgrade on GTR. Not the usual 2.5" N/A HFC you hear everyone destroying with F/I.

No codes are disabled. Even without antifoulers, I throw a catalyst code once in a blue moon..maybe every few thousand miles unless the temps are <50F for a while, which is what led me to try the antifoulers this winter to make sure I passed emissions.