Lean rich condition. New wb sensor and 02 sensors

[2000Phoenix]

Hello, I have a weird lean rich condition that came out of left field. I was re tuning in closed loop since i upgraded to a c5z06 maf everything was going great then the wb and 02 sensors started acting weird. I replaced them all and check for a leak in the exhaust but nothing leaking. Returned table to stock to see if that was the issue but no change. Car is still going super rich .75-.82 and lean 1.15 -1.25 at different times when i start it no matter if i drastically add or remove fuel. Any ideas would be appreciated.

[2000Phoenix]

Here is a second log getting the car off the ramps and jacks. wb and 02 sensors are acting really weird.

[kingtal0n]

Cant look at the log but,

suggested, try Turn off closed loop to see whether the O2 signal behaves normally to isolate the issue to narrowband sensor feedback

[kevin87turbot]

Hello, I have a weird lean rich condition that came out of left field. I was re tuning in closed loop since i upgraded to a c5z06 maf everything was going great then the wb and 02 sensors started acting weird. I replaced them all and check for a leak in the exhaust but nothing leaking. Returned table to stock to see if that was the issue but no change. Car is still going super rich .75-.82 and lean 1.15 -1.25 at different times when i start it no matter if i drastically add or remove fuel. Any ideas would be appreciated.

Since you replaced the MAF, I would start by forcing the computer to SD mode. It could simply be that the new MAF is bad.

[2000Phoenix]

Cant look at the log but,

suggested, try Turn off closed loop to see whether the O2 signal behaves normally to isolate the issue to narrowband sensor feedback

I have gone open and closed loop but the wb and narrow bands are still not reading normal. I am going to have my mechanic smoke test the exhaust as this is the only thing that makes since. I also have a custom reusable fuel filter that I am going to pull and clean. Not sure if a partially clogged fuel filter would cause this but those are really the only two things left I can think of. Evap system in the engine bay looks fine as well. No cracked opened hoses.

[2000Phoenix]

Maf is new and no codes coming up. It was working fine and then narrowbands and widebands went hay wire. My original mass air sensor went out and it through a code and it was different symptoms then what I’m getting now.

[kingtal0n]

If you have an aem wideband and put it into open loop and get a video of the behavior I can give you more suggestions

Anytime the wb O2 suddenly start jumping lean that indicates a misfire,

Maybe try disabling 1 injector/coil at a time and listen to the engine using the scanner

[Hondaeater]

Maf is new and no codes coming up. It was working fine and then narrowbands and widebands went hay wire. My original mass air sensor went out and it through a code and it was different symptoms then what I?m getting now.

Your tune file shows you are in blended mode, but your MAF is not reporting any airmass in the channels list. Check the wiring or scan DTC.
Your injector data, are you running a FPR vacuum referenced? Your offset table is set for returnless non-FPR but the injector IFR is set for FPR vacuum referenced?
Hope that gets you looking in the right direction.
Cheers
Hondaeater.

[2000Phoenix]

Your tune file shows you are in blended mode, but your MAF is not reporting any airmass in the channels list. Check the wiring or scan DTC.
Your injector data, are you running a FPR vacuum referenced? Your offset table is set for returnless non-FPR but the injector IFR is set for FPR vacuum referenced?
Hope that gets you looking in the right direction.
Cheers
Hondaeater.

I?m a little confused on the fpr reference. Injector data is stock 28lb and there is no evap system in the car. Could you clarify as I put the ifr to be steady across the board but you’re saying doing this is opposite to fpr? There was no issues for 100 miles with the mass air sensor also in the video I do shot it around 3000hz at idle before it starts going bay wire.

[2000Phoenix]

I will try to send video of scanner running My mechanic thinks it’s a leak in the exhaust close to that WB and narrow bands. Saids he has seen that a lot but the fuel filter could also cause something like this. You think it could be plugs, wire or a coil pack. Coil packs are msd as well as wires and they are new also. I will try plugs and clean out the fuel filter to see if it fixes it but will still get a video up.

[Hondaeater]

I?m a little confused on the fpr reference. Injector data is stock 28lb and there is no evap system in the car. Could you clarify as I put the ifr to be steady across the board but you?re saying doing this is opposite to fpr? There was no issues for 100 miles with the mass air sensor also in the video I do shot it around 3000hz at idle before it starts going bay wire.

Yes it is wrong if you have a returnless non-FPR vacuum referenced regulator. If you have the fuel filter that incorporates the FP regulator it is not Vacuum referenced and should have a dynamic IFR range. If you did not change the fuel system then do not change the IFR table. To clarify yes the FPR vacuum referenced would have a steady IFR.
stock 2001 Trans Am has returnless IFR.JPG

No MAF airflow and inj does not match tune log 2.JPG Second log off the ramps referenced.... NO MAF airflow reporting, that is a problem and your tune file it is set up as blended mode but the MAF is not failed with the 0 reported airflow?
Injector flow is not consistent with your table either.
I hope you get this sorted out.
Good luck.

[2000Phoenix]

Yes it is wrong if you have a returnless non-FPR vacuum referenced regulator. If you have the fuel filter that incorporates the FP regulator it is not Vacuum referenced and should have a dynamic IFR range. If you did not change the fuel system then do not change the IFR table. To clarify yes the FPR vacuum referenced would have a steady IFR.
stock 2001 Trans Am has returnless IFR.JPG

No MAF airflow and inj does not match tune log 2.JPG Second log off the ramps referenced.... NO MAF airflow reporting, that is a problem and your tune file it is set up as blended mode but the MAF is not failed with the 0 reported airflow?
Injector flow is not consistent with your table either.
I hope you get this sorted out.
Good luck.

Fuel system is completely updated to a race tronics system and the fuel filter is out side of tank and is a custom reusable unit so knowing this the system should be correct or are you saying to switch it back as there was no issue before this? I can switch it back to see but my mechanic is banking on exhaust leak, clogged fuel filter, or possible the plugs. I will switch it back and see what it does.

[Hondaeater]

Why is the IAT Characteristics changed? This is part of the MAP sensor. It does effect the fueling too.

[Hondaeater]

Nope, I was just making you aware of some things that stand out. You do what you need to do. Good luck.
Then you are runing a FPR vacuu referenced regulator yes? The Offset is still set up incorrectly for that.

[Hondaeater]

Since you replaced the MAF, I would start by forcing the computer to SD mode. It could simply be that the new MAF is bad.

yup.

[2000Phoenix]

Per the above I have tried it in open and closed loop and the wb still acts crazy.

[2000Phoenix]

I changed it because when I moved the iat in front of the tb the temp was off. It is now spot per the outside temps.

[2000Phoenix]

No it’s just an upgraded filter as the stock and c5z06 units have gone out on me and my mechanic using this as it is a better built unit.

[2000Phoenix]

Here is a new log in open loop and maf is failed P01 code did throw. The flow rate table was put back to stock as well. Still the same issue.

[gtstorey]

So what are you using to regulate the fuel pressure? Maybe you have answered but I can't pick it out.