Jump to content
SAU Community

Recommended Posts

OK, well it is 2 tank fulls later (800k's) and I can safely say replacing the lambda sensor made no diference what so ever to the fuel economy. It definitely runs nicer, doesn't hesitate when full throttle is applied after long periods of idling (damn Sydney traffic) and cruising. But fuel ecomomy is totally unchanged.

Gotta get that exhaust on and tune it up some more on the dyno. Just need a spare few hours.

:( cheers :)

  • 9 months later...
Nissan recommends changing them every 40,000k's. They don't "wear out" in a mechanical sense. They just get contaminated and don't read the A/F ratios properly.

Interesting to say the least. So how do you know when to replace them? It's not cheap enough just to do it for the sake of it.

How sensitive are they to being knocked around. A friend dropped his once on the bench and it would not work properly after that. I recently dropped mine while doing the dump pipe upgrade - How do I know it is still working?

Would really be interested to know how they work internally?

They use some sort of chemical reaction to create a voltage once they are at the right temperature (which is why they have heater wires as well) THe chemicals get tired after a while and dont work anymore.

The best way to tell if its stuffed is to use a consult cable to monitor the voltage, stuffed ones read 0 or jump around at odd times. Unfortunately working ones jump around a bit too so it is hard to tell if it is dying unless you have a gtr (2 sensors so you can compare voltage)

  • 1 month later...

I took my car out to CRD to get tuned a week ago - they told me my o2 sensor was stuffed and told me a new one would cost $300+ as well as labour charge.

I get <200kms from a tank, if the o2 sensor was stuffed when they tuned it, does that mean it needs tuning again when i put my new o2 sensor in? or does the wide band one they use for tuning mean that it would have been tuned nicely anyway?

If i replace a stuffed o2 sensor should i immediately see an improvement in fuel economy?

Does anyone have an online link to buy an o2 sensor online? to save me a trip to repco...

And is their any adavantage to buying the genuine nissan part as opposed to the falcon part?

i have a falcon one and it works fine, no problems.

Thanks terminal - im thinking i will try to get a genuine part, or at least one that i dont have to change the wires on, would cost me more to get someone to change the falcon one over than it would to spend the extra on the genuine part.

I am taking it that all of this advice is relevant to R33 gts-t owners, not specifically stageas?

Thanks terminal - im thinking i will try to get a genuine part, or at least one that i dont have to change the wires on, would cost me more to get someone to change the falcon one over than it would to spend the extra on the genuine part.

I am taking it that all of this advice is relevant to R33 gts-t owners, not specifically stageas?

The Falcon lambda sensor I used cost $78 from Repco. last time I checked the genuine Nissan one was $180. I don't think anyone is going to charge you $102 to swap over a plug, it's a 10 minute job.

:) Cheers :P

The Falcon lambda sensor I used cost $78 from Repco. last time I checked the genuine Nissan one was $180. I don't think anyone is going to charge you $102 to swap over a plug, it's a 10 minute job.

:) Cheers :)

Change of plan

I bought a falcon sensor from Repco i think it only cost me $58 (hope its the right one)

The auto elec is charging me about $70 to fit it... It was going to be a 2 week wait for the genuine nissan part.

Quick question, can the power FC be tuned with a faulty o2 sensor? i.e. does the wide band sensor they stick in the exhaust mean that it doenst matter about the faulty one up front?

The reason i ask this is because i just paid for my car to be tuned, and when i rang up complaining about fuel issues they told me my o2 sensor was buggered... So did they tune it right and the new sensor will fix my problems? or did i get ripped off?

Change of plan

I bought a falcon sensor from Repco i think it only cost me $58 (hope its the right one)

The auto elec is charging me about $70 to fit it... It was going to be a 2 week wait for the genuine nissan part.

Quick question, can the power FC be tuned with a faulty o2 sensor? i.e. does the wide band sensor they stick in the exhaust mean that it doenst matter about the faulty one up front?

The reason i ask this is because i just paid for my car to be tuned, and when i rang up complaining about fuel issues they told me my o2 sensor was buggered... So did they tune it right and the new sensor will fix my problems? or did i get ripped off?

Depends on what fuel issues you were complaining about, all the tuning under load they'd have used their Wideband O2 for, and your factory narrowband isn't part of the equation. But if your mixtures are wrong under light load and idle, and the Power FC is setup to use closed loop with the factory narrowband, then a stuffed one would be a problem yep.

How do you mean you've got fuel issues?

Depends on what fuel issues you were complaining about, all the tuning under load they'd have used their Wideband O2 for, and your factory narrowband isn't part of the equation. But if your mixtures are wrong under light load and idle, and the Power FC is setup to use closed loop with the factory narrowband, then a stuffed one would be a problem yep.

How do you mean you've got fuel issues?

Fuel issues are only getting 200km per tank which is costing me a fortune. doesnt seem to matter how i drive it (hard or soft) i still get terrible fuel economy... having a new o2 sensor installed as we speak

Fuel issues are only getting 200km per tank which is costing me a fortune. doesnt seem to matter how i drive it (hard or soft) i still get terrible fuel economy... having a new o2 sensor installed as we speak

Then they could be talking about lack of closed loop control giving you poor cruise/idle fuel economy(due to stuffed O2). Generally in a full tune, they would input fuel values for all conditions that were close to ideal, so you shouldn't get shocking fuel economy after a good tune, even without closed loop control.

I don't get heaps better than that myself (used 16L to do 71km's around town the other day, but prob too much boosting). But anyway, I thought mine was too rich, and thought factory O2 was stuffed. Last night I put my LC-1 Wideband O2 sensor on it and went for a drive, 14.5:1 under all idle and cruise conditions! That surprised me, thought it'd be far worse.

Would be very much to your advantage if you could borrow/buy an Innovate Motorsports LM-1/LC-1 and analyse your mixtures, then you'd know before/after, and not have to put all trust in what the workshop tells you. Not too mention you'd then have crucial gear for tuning your ecu yourself if you ever wanted to.

I reluctantly paid $400 (NZ) for mine(and display it on my old laptop), but now I love it and can't imagine not buying it, I'd have no idea what my cars are doing!

Bottomline, it's hard to diagnose fuel troubles, especially with an aftermarket ecu, without some kind of AF reading gear.

Let’s clear up this “closed loop tuning” issue. There is no such thing as “closed loop tuning”, the standard ECU has a simple lambda aim table loaded into its mapping. In a Power FC that is in fact one number, around 15 to 1 A/F ratio.

This means whenever the parameters are met (idle or cruise) the ECU reads of the standard (narrow and slow) lambda sensor and tries to hit the targeted A/F ratio. So it increases or decreases the injector duration continuously trying to keep at 15 to 1. As long as the lambda sensor is working correctly the ECU will always aim for its target A/F ratio, hence there is no tuning required.

Remember with all closed loop running it doesn’t happen instantly, the throttle opening has to be constant, the rpm has to be stable and the (slow and narrow) lambda sensor has to have enough time to read off the A/F ratio and tell the ECU what it is.

This is where a slight improvement in fuel economy can be gained by utilising a fast and wide lambda sensor. By tuning the fuel map locations around the closed loop location (idle and cruise) to give around 15 to 1 A/F ratios. This means that you save that little extra fuel while the ECU is fiddling around reading the lambda sensor etc.

If you have a read of the Tech Edge thread in Forced Induction, I go into some detail on how I tuned the idle and cruise A/F ratios.

:devil: cheers :down:

Fuel issues are only getting 200km per tank which is costing me a fortune. doesnt seem to matter how i drive it (hard or soft) i still get terrible fuel economy... having a new o2 sensor installed as we speak

A perfectly working lambda sensor is unlikely to improve the fuel economy from 200 k's per tank. Maybe 20 k's, depending on how much time you spend at cruise or idle. If it's a lot of the time while you are driving, then you might get 15%, but if you spend hardly any time idling and cruising then it won't make much difference at all.

Personally my guess would be you have other problems, not the least of which is tuning.

:devil: cheers :down:

A perfectly working lambda sensor is unlikely to improve the fuel economy from 200 k's per tank. Maybe 20 k's, depending on how much time you spend at cruise or idle. If it's a lot of the time while you are driving, then you might get 15%, but if you spend hardly any time idling and cruising then it won't make much difference at all.

Personally my guess would be you have other problems, not the least of which is tuning.

:wave: cheers :D

I just paid to have it tuned...

Is there anything else it could be?

I spend a lot of time at idle, but not much at cruise... i cant afford to keep running the car like this.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Hi all,   long time listener, first time caller   i was wondering if anyone can help me identify a transistor on the climate control unit board that decided to fry itself   I've circled it in the attached photo   any help would be appreciated
    • I mean, I got two VASS engineers to refuse to cert my own coilovers stating those very laws. Appendix B makes it pretty clear what it considers 'Variable Suspension' to be. In my lived experience they can't certify something that isn't actually in the list as something that requires certification. In the VASS engineering checklist they have to complete (LS3/NCOP11) and sign on there is nothing there. All the references inside NCOP11 state that if it's variable by the driver that height needs to maintain 100mm while the car is in motion. It states the car is lowered lowering blocks and other types of things are acceptable. Dialling out a shock is about as 'user adjustable' as changing any other suspension component lol. I wanted to have it signed off to dissuade HWP and RWC testers to state the suspension is legal to avoid having this discussion with them. The real problem is that Police and RWC/Pink/Blue slip people will say it needs engineering, and the engineers will state it doesn't need engineering. It is hugely irritating when aforementioned people get all "i know the rules mate feck off" when they don't, and the actual engineers are pleasant as all hell and do know the rules. Cars failing RWC for things that aren't listed in the RWC requirements is another thing here entirely!
    • I don't. I mean, mine's not a GTR, but it is a 32 with a lot of GTR stuff on it. But regardless, I typically buy from local suppliers. Getting stuff from Japan is seldom worth the pain. Buying from RHDJapan usually ends up in the final total of your basket being about double what you thought it would be, after all the bullshit fees and such are added on.
    • The hydrocarbon component of E10 can be shittier, and is in fact, shittier, than that used in normal 91RON fuel. That's because the octane boost provided by the ethanol allows them to use stuff that doesn't make the grade without the help. The 1c/L saving typically available on E10 is going to be massively overridden by the increased consumption caused by the ethanol and the crappier HC (ie the HCs will be less dense, meaning that there will definitely be less energy per unit volume than for more dense HCs). That is one of the reasons why P98 will return better fuel consumption than 91 does, even with the ignition timing completely fixed. There is more energy per unit volume because the HCs used in 98 are higher density than in the lawnmower fuel.
    • No, I'd suggest that that is the checklist for pneumatic/hydraulic adjustable systems. I would say, based on my years of reading and complying with Australian Standards and similar regulations, that the narrow interpretation of Clause 3.2 b would be the preferred/expected/intended one, by the author, and those using the standard. Wishful thinking need not apply.
×
×
  • Create New...