Jump to content
SAU Community

Recommended Posts

Hi,

Car is running rich and not smooth (acceleration, hesitation etc). I am thinking it's the o2 sensors.

My car is a r34 gtr and it currently has a power fc installed and tuned recently.

First question, when dyno tuning, do the tuners take into account the o2 sensors?

I decided to disconnect both o2 sensors and went for a drive, it feels perfect!

Second question, driving without o2 sensors connected, is it bad for the engine? (my car is running rich with the sensors connected anyway, i dont have any way to check air fuel ratios)

Thirdly, can I conclude that the o2 sensors are faulty?

Finally, I want to replace my o2 sensors anyway... I know I need the zirconia ones. Both sensors are they same right? Just different plugs? (One square, one oval?) Can someone please point me to a link or a place to buy a pair of them?

Thanks alot guys!

Link to comment
https://www.sau.com.au/forums/topic/458174-r34-gtr-o2-sensor-problem/
Share on other sites

You should do some more searching as all those answers can be solved pretty quickly but I can summarize I guess.

1. You have a PowerFC so you should get ahold of the FAQ guide and you can actually go through the menu and check to see if your O2 senors are working from a Hand Controller. When Dyno Tuning, the sensors are either turned on or off basically as they are set to open or closed loop. When they are on they just trim fuel on cruise loads to increase fuel efficiency basically. Research some more if you want to learn more. If your tuner is good you can just turn them off and tune with the sensors and get the results you want anyway.

2. You can test oxygen sensors to see if they are faulty with a multimeter, if you get a very small voltage they are not working, forget what the actual range is. Search for how what values to look for a what wires (of the 3) to check.

3. You need the correct sensors for your GTR, which if it isn't a 32, you use zirconia ones. The 32 ones use a different composite and they don't work for the 33/34. Look up Kudos motorsport as they sell OEM senors. Could source elsewhere from Japan cheaper if you are keen. I wouldn't bother replacing them unless they are actually not working though. Do the test first.

4. Your car should be running rich (not excessive though) so if anything not having an O2 sensor would just make your fuel efficiency worse if it hasn't been compensated for by the tuner and you unplug the sensor. You might get fault codes and other stuff appear but there shouldn't be any real problems as far as I know.

5. Get a wide band for your car so you can measure and read AFR values while driving if you want. Very handy for tuning and detecting fuel issues that may occur. The PowerFC Hand Controller is very useful if you know how to use and read off it. Wouldn't suggest making any changes as they are only temporary from the controller anyway, but good to understand what you can monitor and see in case you have any problems that come up.

In short, you can just ask your tuner if he has it set to closed/open loop or how he set the tune up as he should know. Liked stated in the dot points, the car should run rich but not to a ridiculous point. If you have concerns after fixing/checking O2 sensors raise it with your tuner maybe.

Edited by breaker1845

Thanks for that! Haven't had the chance to talk to my tuner yet...

The thing is with the o2 sensors connected.. it is running excessively rich, as in... 250km a full tank on a r34 gtr.

WITHOUT the o2 sensors connected, it is running fine.. and I can see an improvement in millage already. (Haven't finish the tank yet)

I know that running rich is somewhat fine, I just don't want it to run lean.

Think what I'm really asking is.. can I just run my car with the o2 sensors disconnected till I can find new o2 sensors as a temporary fix?

If it really is your O2 sensor, you can disable it via power fc hand controller anyway without having to physically unplug it

Some people here don't run O2 sensors including myself provided your tuner has done a good job.

My understanding is that closed loop is only applied during cruising and idle after car warms up, so it shouldn't affect your car too much if you disable it, unless your tune is really off in the cruising cells, which is unlikely but then again no one can confirm that except for your tuner

Check your PowerFC first to see if they are even switched on because if they aren't, unplugging them shouldn't do anything.

Also poor fuel consumption may not just be O2 sensors, other components can affect that too. But you did say you had some issues with hesitation and such that you believe is cleared once you disable the oxygen sensors.

If you have time, discussing with your tuner about your level of satisfaction or what you have discovered about the tune may also help if it was recently done.

You won't run lean disconnecting the o2 sensors either if that is your concern. You can order new sensors if you want from Kudos and they usually arrive at your door within a few days.

If the sensors are buggered (you can check readings from PowerFC or manually) then effectively if they are on and you disconnect them it would be beneficial, which I suspect could be your case.

http://www.ebay.com.au/itm/Front-NTK-OXYGEN-O2-SENSOR-NISSAN-R33-R34-GTR-RB26DETT-lambda-oxy-cyl-4-6-/111455121782?pt=LH_DefaultDomain_15&hash=item19f33e3176

Can someone please confirm that these are the sensors I need?

Front and rear sensors are the same but different plug design.

I need to order two of them, however because of the plug design, I have to cut and connect to existing plugs?

Thanks guys. Once I get a response, I'll order them right away.

http://www.ebay.com.au/itm/Front-NTK-OXYGEN-O2-SENSOR-NISSAN-R33-R34-GTR-RB26DETT-lambda-oxy-cyl-4-6-/111455121782?pt=LH_DefaultDomain_15&hash=item19f33e3176

Can someone please confirm that these are the sensors I need?

Front and rear sensors are the same but different plug design.

I need to order two of them, however because of the plug design, I have to cut and connect to existing plugs?

Thanks guys. Once I get a response, I'll order them right away.

Check with your tuner first. When my Link was installed the O2 sensor was removed as the ECU takes care of the idle and cruise. You may not need to spend the money.

Never used O2s, only had them there to keep the Poleeece happy.

A decent tuner will tune better than what the O2 will provide in terms of "trim" etc. So go back and talk to them. Don't go spending money if you don't need it, and really, you shouldn't.

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

    • Yeah, the latter. No diff should have a centre replaced without checking clearances because its unlikely to be the same as whatever came out. Not that that stops most people just checking a new centre in
    • Major thread necro but how bad of a job is it to DIY? Looking at it online it looks like if you reuse your ring and pinion as long as those are in good condition it should be fine to just pull the axles/front cover and replace the diff that way? Or should I be replacing everything and doing preload measurements/gear mesh testing like the factory service manual mentions for the rear diff?
    • in my list I had the R33 GTR as the best Skyline. Infact I had all GTR's (33>34=32), the NSX, the GTO, the 300ZX, the 180SX, the S15 better than the FD RX7. I had the MR2 and the A80 as 'just' better. I also think the DC5R Integra looks better but this is an 01 onwards car. I also think the FC>FD. It's almost like aesthetics are individual! The elements @GTSBoy likes about the FD and dislikes about the 180 are inverse in my eyes. I hate the rear end of the FD and it's weird tail lights that are bulbous and remind me of early hyundai excels. They are not striking, nor iconic, nor retro cool. The GTO has supercar proportions. I maintain these look much better in person (like the NSX) especially with nice wheels and suspension which is mandatory for all cars pretty much. Some (or all) of these you have to see in person to appreciate. You can't write a car off until you see one in the flesh IMO. Like most people we probably just like/dislike cars which represent certain eras of design or design styles in general. I also think the 60's Jag E type looks HORRIBLE, literally disgusting, and the 2000GT is nothing to write home about. FWIW I don't think the Dodge Viper Gen1's have aged very well either. You can probably see where I rate bubbly coupes like the FD. I know we're straying now but the C4 and C5 absolutely murder the Viper in the looks department as time goes on, for my eyes. Wouldn't surprise me if people who love the FD, also love the MX5, Dodge Viper, Jag E Type, etc etc.
    • I used to hate R31s, and any of the other Nissans that led up to it, and any of the Toyotas with similar styling, because of the boxiness. They were, and remain, childish, simplistic, and generally awful. I appreciate R31s a lot more now, but only the JDM 2 door. The ADM 4 door (and any other 4 door, even if they are unique compared to our local one) can eat a bowl of dicks. The Aussie R31 is also forever tarnished by their association with stereotypical bong clutching Aussie R31 owners of the 90s and early 2000s. I think the Nissans of the 70s (other than 120Y/180B/200B) are far superior looking to the 80s cars. The 240K era Skylines are boss. The same is broadly true of Toyotas. Hondas don't ever register in my thinking, from any era. Mitsus are all horrid shitboxen in any era, and so also don't register. Subarus are always awful, ditto. Daihatsus and Suzukis also don't generally register. They are all invisible. I think the SW20 MR2 looks fiddly. The 3000GT/GTO is like that but way worse. Too many silly plastic barnacles and fiddly gimmicks ruined what could have been a really nice base shape. Kinda-sorta looks like a big heavy ST165 Celica coupe (and I'm not sure if that's a good thing or a bad thing). I think the 180SX is dreadfully bland. It's not bad looking. But it has no excitement to it at all. It's just a liftback coupe thing with no interest in its lines, and bad graphical elements (ie wide expanses of taillight plastic on the rear garnish). The S13 Silvia is a little better - getting closer to R32 shapes. But still....bland. S14? Nope. Don't love it. S15...a little better. Probably a lot better, actually. Benefits from not being like a shrunk in the wash R34 (where the S13 was a shrunk in the wash R32 and the S14 looked like a Pulsar or something else from the stable on Nissan mid 90s horrors). The Z32 was hot as f**k when it came out but hasn't aged as well as the A80. Keep in mind that I think the R33 is the most disgusting looking thing - and out of all the previous cars mentioned is objectively closest to my precious R32. It's just....real bad, almost everywhere you look. And that is down to the majority of what was designed in the 90s being shit. All Nissans from that era look like shit. Most other brands ditto. In that context, the FD absolutely stands out as being by far the best looking car, for reasons already discussed. Going behind the aesthetics, the suspension alone makes it better than almost any other car.  
    • If they just called it the "Mazda Tiffany", it would have been spot on.
×
×
  • Create New...