Fitting A New Lambda Sensor

[AlexCim]

yes, im pretty sure thats right, from memory...

[MYS013]

Fantastic thanks, just looking to order one for my car.

[Sydneykid]

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

[AlexCim]

Ive gone through my first tank...but what i have understood is that my stagea drinks heaps under load, so i have been off the throttle a bit, just being a granny.

I do say though that now, i dont have o2 to worry about

[Sydneykid]

Quite a few guys recently have asked me about this thread via PM. So I figured it was time to bump it up the list a bit.

cheers

Edited June 22, 2006 by Sydneykid

[Ska]

Thanks SK, added to the Stagea DIY collection thread:

http://www.skylinesaustralia.com/forums/in...howtopic=102808

[3intheBack]

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?

[Duncan]

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)

[Trooper]

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?

[Terminal]

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

[Trooper]

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?

[Sydneykid]

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

[Trooper]

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?

[Spammeoff]

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?

[Trooper]

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

[Ska]

If you have a power-fc and get it properly tuned, I got ~550km out of my tank, BUT under certain circumstances, read:

http://www.skylinesaustralia.com/forums/in...t&p=2388688

[Spammeoff]

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.

[Sydneykid]

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.

cheers

[Sydneykid]

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.

cheers

[Trooper]

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.

cheers

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.