AWESOME!!! Damn it, after looking at my TT install pics and looking at the G35 tech manual I pretty much figured this, oh well, if they gotta come out, they gotta come out ...

Hey, thanks for all of the help

I'll keep you posted

 

Which EMS are you using? I think my front O2 sensors may be going bad, but quite frankly they are not used (running the Haltech) so I'm trying to get an Osiris flash to just eliminate all the CEL codes associated with closed loop O2 control and those sensors. Besides which there is basically no way to get to those sensors without dropping the tranny or the motor (for my set up, which is custom).

 

I'm running Utec, are you saying that the Haltech has no closed loop functionality? If it does then it'll have to get an AF reading from some sensor ...

Edit: Just found this ... do you have dual WB's further down the system somewhere?

Some Key Points for the HalTech Platinum PnP EMS:
• End User Tunable (not locked like some EMS on the market)
• Sequential Fuel and Ignition Control (32x32)
• Cylinder Trim Tables for each injector and ignition coil (8x8)
• Coolant and Air Temp Correction for fuel and ignition
• Complete Intake and Exhaust Cam Control (03-05’ Intake Cam control only) (24x24)
• Configurable Load and RPM points for all tuning tables
• Tuning via MAF, TPS, or MAP
• Fuel tuning by Volumetric Efficiency (VE) or Injection Time (MS)
• Injector drivers operate both Saturated and Peak & Hold injectors
• Map Trace
• Knock Detection
• Overboost Protection
• Open/Closed Loop Boost Control
• Dual Closed Loop 02 Control
• Onboard Data Logging
• USB Communication (no outdated Serial cable required)
• New Windows Tuning Software, ‘Haltech ECU Manager’
• 32Bit Microprocessor, 55MHz
• Plug and Play Loom
• Auxiliary two-step rev limiter
• User Configurable Inputs and Outputs (coming soon in a free software update)
• Nitrous and Meth Injection Control (coming soon in a free software update)
• Knock Control (coming soon in a free software update)

 

Well I do have a tuner reg (TXS) but I do not have the Haltech connected to it (though you can attach one wideband to both bank inputs of the Haltech).

It's my understanding that the Haltech is reading AFR from the rear O2 sensors. Perhaps I am mistaken though. The Haltech shows me that the stock widebands are really close in reading to my TXS unit, so if they really represent the front pair, then they are probably not failing. I get all sorts of codes related to closed loop control that I am reflashing with Osiris for though.

If Hal sees this post perhaps he can clarify which set of O2 sensors are used for closed loop control...

 

Well, changed out the primary O2 sensors (which are widebands on my 04.5 G) and all is good again, thanks to all for your help, this is definately something that would not have been on my radar.

 

Glad to see you got this fixed. I've been having O2 sensor codes come up on my car since adding my vortech. I just reset my ECU today, and have driven 50 miles without throwing the CEL so far. This is my longest run yet. The only thing diifferent from before is I added the 2.87 pulley and 99 octane till I get retuned. I think it hasn't come on because I'm not running as rich as before.

 

Glad i/we could be of help.

 

I was mistaken - you were correct. The Haltech uses closed loop feedback from the front two sensors.

What is the difference between the front two and the rear two? One is fast switching and the other is slower, correct?

How did you know which O2 sensor to swap out: front, rear, bank 1 (pass), or bank 2 (driver). Based on the CEL code?

Did you find a good source for sensors?

 

on 04.5 and newer models the front 02 sensors are wideband sensors

 

So you're saying the front are wideband and the rear are narrow band? I also have a 04.5.

My closed loop seems to be working fine (as confirmed by my tuner reg wideband) but if I datalog the curves from bank 1 to bank 2 look really different (though values are close at any given moment between banks). I am also getting CEL codes related to bank 1.

 

The front O2 sensors are used for closed loop, the rears are to figure out if your cats are working efficiently or not ...

I bought my new O2's from Infiniti dealership for $180 bucks a pop, and yes I could have found them cheaper but I was in a time crunch ...

If you are getting a CEL code it's hard to tell if it's the fronts or backs but if the fronts are going then your closed loop response will be lagging and you will be frequently running rich which will make you rears unhappy and report ineffeciencies in the system ...

 

Ok, try this, if you have a wideband display in your car, let the car idle and then blip the throttle, if the AFR wildly swings about and gradually gets back to 14.7 then there is a good chance that the response times of you front O2's are getting slow.