Its nice to know that the rear O2 sensors should be deleted. I'm getting the occasional check engine light with reference to the rear O2 sensors so before I shell out another 200 bucks to replace it, I will stay tuned to this thread. Great work Mitch.

R.K.

Thanks Rad. Pretty much its looking like those Rear O2s are just a check for the Cat functions. No cats no need to have the ECU check them. I think I am going to get some plugs and remove mine completely here next time I am under the car just to clean it up so they do not snag on anything.

Just an update for mine I have removed the Rear O2's and it has been idling just fine now my wideband reads 14.0 - 14.9. Now I just have to remove that code that came up from that and it is looking good. Thanks for finding this fix Mitco39.

I must be retarded but none of the fuel trims you are referring to bar options on my cipher. would it matter that I only have a standard cable?

Glad it has worked out for you, let me know if you need a hand getting the codes gone. It should be as simple as just turning them off, I can include screenshots if you wish.

They might call it something different with cipher, it should still be able to see these PIDS however. Ill check this weekend for you.

I will probably bring the car to the track tonight and do a few more runs in her. I will also play with the hot starts tonight and see if I can find a happy medium between hot starts and lean out conditions during idling. This is if it does not storm here tonight, there is a 40% chance :shakes head:

Totally forgot to check this out for you jwick, ill do it tonight if I can remember. I am dropping my car off to get detailed this week so ill be without it most of the week.

I can tell you guys that the bad start has been fixed and it was never related to the tune, it was just a coincidence that it started to happen right around the same time. One of the wires from the fuel pump relay was coming loose from where it connects to the relay block. Got that all fixed and she starts right up just fine every time. I started 3 times back to back to back and it will good to go.

Also even driving like a toolbag at times my mileage has gone way way up after I dialed my tune in. It no longer idles or cruises rich. The hunting has almost all but stopped (still a slight hunt which I would attribute to the rerouting of the crankcase emissions system and removing it from the intake. Unfortunately there is no way to tweak the settings responsible for this. It could be the vvel doing its best to control the idle. Its minimal though compared to what it once was.

awesome mitch. I can't wait to discuss this with tuner.

I've been thinking the crank case being directly vented instead of rerouted into the system might be causing issues too. wonder if there is any way we could find a way to rig them back in. I know the GTM kit routes them back in. I believe its pre-turbo. that would be impossible for us since the filter is directly on the turbo.

My car has been at a detailers all week and my cable is in the car so I havent had uprev infront of me for a bit.

But if you were going to route that vent back it would have to be under a vac only condition so you dont pressurize the crankcase more than necessary.

You could do this via a PCV valve so that when your under boost it keeps the boost out of the crankcase, but under vac it sucks in the crankcase emissions. I had it all figured out in my head last year and there is a thread that I believe I started on it. I will dig through it and see what I can come up with when I get time.

Although I personally think if we had access to the IAC tables we could tune for the idle. I also believe the VVEL does not help us. Does anyone have any experience with say sashas kit on the 350Z where the crankcase ventilation is also routed in a similar fashion?


Mitch

Sorry if I'm asking a repeated question but is this problem only related to BP kits? Minor problem which I hope tuner could fix soon.

Mitch - Figured I would bring this thread back to life and see how things are working since it's been over a month since you made the changes to O2 sensor removal and 'cold' settings.

How's the car running? Still have any symptoms?

Ever find a fix for the hiccup or is the going theory still that the missing PCV system is causing it?

Still think it would be helpful if several of the BP guys could post log files of identical conditions (i.e. same parameters and idling conditions)

Did the modifications to the cranking table end up fixing your hot start issues?

The more I look at the log request list above the more I think the tuner cable provides a few more options.

Without typing them all out, pg 8 of the Cipher manual recommends the following parameters to get an eTune directly from UpRev. There are obviously some not needed (speed, coolant, speed, throttle position, etc.) but would this list provide the stuff you originally asked for?

http://uprev.com/UpdateFiles/softwar...er%20Guide.pdf

I brought this back to life because for two reasons. First, I'd really like the feedback and hopefully know if this is a good fix I should add to my next retune. Second, I kind of believe that all this still ties into my having the P2A00 code for the O2 sensor.

The idle is much much better, it still does a bit of the hunt but its 75% better I would say. It no longer sounds like its working its a$$ off just to stay running. 0 other issues related to deleting those O2s to date.



Still think it would be helpful if several of the BP guys could post log files of identical conditions (i.e. same parameters and idling conditions)



To be honest with you I have just been living with the hot start issue right now. But when I go and retune for these 3" charge pipes I will take a look at it. I believe its just overfuelling right now right in the cranking area. Starts great when cold, and starts fine when you turn it on after its been off for a short time. But if you let it sit and get heatsoaked she struggles at times. Im confident its just flooding itself. I also have not changed my plugs since going boosted and running sub 10:1 at times so its on the table to replace my plugs around the same time. Infact I should order up some today.


Yes it is, sorry I never got back to you on how to get a log. I took a few screnshots and ill put them together in a mini guide for you.


I am pretty confident it could very well be related to your issues with that code. Reading up on it briefly its directly related to the switching of the O2 from lean to rich, which is what the car is struggling to do with those secondary 02s fighting you.

OBDII Code P2A00 - O2 Sensor Circuit Range/Performance Bank 1 Sensor 1 | Nissanhelp.com

I'll do some idle logging this weekend.

I might pull post cat sensors if I can get my tuner to update my map.

Jwick,

Open up your rom editor then once its connected to the car click the logging button as shown.

http://img.photobucket.com/albums/v2...ps7f3b912b.jpg


Then from there you can select all the parameters you want to log. Hit record then when you are done you can stop the recording and save the log. THe log is saved in a CSV form that can be open with microsoft excel.

http://img.photobucket.com/albums/v2...ps79730a46.jpg

Logging is not an issue. Although mine looks way different than that. It must be that I have the standard package and not tuner. I'll pull the parameters I can but I'm pretty sure 'Target AFR' is not an option on the standard cable.

I'm having the same issue! This didn't start until I replaced the passenger side throttle body. I was then instructed by R/T tuning that I needed to do a throttle body relearn but I was unable to because Nissan couldn't access my ecu because of the custom tune. Well since I live 3 hours away from R/T tuning they emailed me a manual relearn process which I had Nissan do because I received the email the same day the car was in for service. When I got the car back everything seemed fine until the first attempt to turn on the AC. As soon as I flipped the switch the car started this issue and has been like that ever since. I even took it all the way back to Lansdale PA (r/t) and of course the car wasn't doing it when I was there so they were unable to fix it but the car eventually did throw a code which was for a low idle. So it's my belief that when the car went through the manual relearn process the idle was set too low but r/t disagreed. All I'm sure of is everything was fine before the relearn and now it seems like it's going to stall out at low rpm's and runs really rich at times

What kit are you running?

I'm all stillen. Every performance part stillen makes for a 7at 370z is on my car. Also Vince at r/t told me to clean my filters and mafs so I did and that did nothing.

Wonder if the issues are similar.

The only thing I'm sure of is I spent too much time and money to have my car sound like its broken

Word!

I guess there is some solace in the fact that galeforce is having the same issue. Not to be taken negatively. If he's having this issue with his extensive knowledge and experience with modifying 370s then I don't feel so bad

I guess ill just stop contributing to this topic. I will get to the bottom of this idle, I have a bunch of theories but I am limited by what I have to work with what tables Uprev gives their "non pro tuners".


Jason, how much you pay this guy? lol.

No Mitch please don't. Some of us know the truth:tiphat:

And :bowrofl::bowrofl::bowrofl:

lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues.

Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system.

One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.

I hear you! Other than us providing alternate data points you are the driver of what's going on in the progress of a solution :tiphat: My man!

Question - Can you route the PCV back into the intake tubes? The only reason I ask this is because the GTM TT kit has them routed in the air filter tubes pre-turbo. From the experience I have with those kits, they aren't having the issues we are.

That being said, I don't know how we do that since the filter is clamped directly to the compressor inlet.

I'm definitely down for a solution. I'd happily tap my intake piping for the PCV system if it'll take care of the hiccup.

Just looking at the service manual now... It has 2 crankcase ventilation systems working together. Im not sure if my idea of putting it into the intake would be sufficient. Right now I bet the car is drawing unmetered air in through the lets call it primary ventilation circuit through the intake manifold. Now with the secondary ventilation circuit to atmosphere one could assume that its sucking air in through this secondary vent circuit into the crankcase then out through the PCV valve and into the intake manifold. Ill find a picture and post it up explaining that.

This would allow unmetered air to make its way into the engine, although when a engine idling it is supposed to be in closed loop which shouldn't affect its operation to much, however if the vacuum pressure in the manifold is changing slightly it would change the combustion process enough that could cause the hunt as it continually tries to stabilize itself.

I like thinking problems, lol.

Mitco39, I am guessing your thinking of adding something like this: mpx_check_valve then route the PCV back into the intakes, kind of like the OEM intakes do?

My engineer brain is going to have to see a visual that I can then link back to my familiarity of the engine bay to understand exactly what you just said. Caught the meaning but not the actuallys

That's my working understanding too. You need the check since we would be tying in where you can see positive pressure. Treadstone makes something similar.

[QUOTE=Mitco39;2939877]lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues.

Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system.

One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.[/QUOTfE]


Apparently I missed something. I'm guessing I rubbed you the wrong way. I mentioned Jason in my post because he was the op of this particular thread even though he just quoted you. Didn't mean to belittle your efforts or rub you in any way..

Upon looking at it more closely I have a check I am going to try. I am just going to pull off what I refer to as the primary circuit and vent it to atm. That will stop any chance of this sort of thing happening. Right now I believe all the kits keep this circuit so that they are not blowing out oily emissions all down the car.

What I am referring to as the primary circuit is the purple highlight, green is the secondary with the filters on it currently.

http://img.photobucket.com/albums/v2...psbfd0fc59.jpg

Thats what I was thinking of at first yes. And might still have to try something like that. Or might just delete the PVC system all together, although then its a question of what to do with the oily mess it leaves.

Your an engineer as well? Awesome. I am a Mechanical Engineer working on structural design for drilling rigs. Although the automotive field is where I want to be some day.

See the pic tells a thousand words. So the primary is the two that tie into the IM right where we tapped for the BOV feed. That must not have as much of an effect on the system as the secondary because all the kits I know of keep that setup.

That's pretty funny. I'm structural but working as a facilities engineer on offshore platforms. Small world:tup:

I think we each have each others jobs:rofl2:

yes they tie in there and under idle the manifold is under a vacuum that sucks in crankcase vapors. Now before the kit the crankcase would be filled with air from the intake between the maf and the throttle body. But now this air is just entering the system through those two fiilters and straight into the intake at idle.

Just throwing ideas out. Partially for my understanding and partially to see if any trigger some light bulb in your mind that leads us to a solution. I could be completely off but stick with me. So NA it's pulling metered air in from the intake (post-MAF). I would guess the ECU is expecting a certain amount of air to be removed from what it's metering, where in reality (vented) the crankcase is pulling in as much unmetered air as it wants. There is no adjustment for that air not being removed and when you come off throttle it hiccups because it's getting more air than it expects leading to the lean condition. Which is what we see happening.

But let me throw an additional monkey wrench. The GTM kit ties that secondary in pre-MAF, so it has to be something different or in addition to what I stated above or there is something in the tuning that can correct for that.

You could be right, as the car switches from open loop to close loop it could cause a hiccup until it stabilizes itself. Easy way to try and see if this is causing it is to pull both lines and plug the ports in the intake manifold and idle the car and see what happens. You could just vicegrip the lines to and let the secondary system do all the venting. I am going to try that this weekend and see what the car does.

Is that secondary drawn in pre-turbo? It could be that there is enough vac pre turbo to keep the air being drawn through that system to minimum. But your right the same principle applies in this case as well. Its a head scratcher for sure. Ill try and get some time tonight with the car.

As I understand it, yes pre-turbo. My buddy has a GTM TT and he tells me its routed in the intake filter tube before the turbo. I'm almost positive he's correct too because you can clearly see the upper pipe (IC) and that's not where it's tied in.