Difference in economy

[kazman]

Hey guys,

Might not be a technical question, not sure.

When I bought some kaizen garage extractors and put them in I didn't get my o2 sensor welded back in. I'd heard people say it wouldn't make much of a difference on a 16v. Now I had some old 4-2-1 TRD's and I used to average 300-400km a tank. Now I'm struggling to get 300-350km with the new extractors and no o2 sensor.

Also it seems to surge between gears when I'm putting the foot flat to the floor, also when I go from no pedal to full pedal, sorta hesitates then gets up and moves, is it running rich?

Thanks.

Also another quick question. I've got a T-series diff, if I'm doing 110km/h and it sits on 3,500. What sort of diff gears could I have, 3.9?

[Medicine_Man]

Of course it will run rich, It has no idea on how the fuel is burning without the 02 sensor. All it is going to do is meter the fueling off the MAP Sensor or AFM.. and even then it will give it more fuel to ensure it doesn't lean out..

[4door]

dinal drive is possibly a 4.1 or 4.3

i am just guessing this tho

[parrot]

<div class='quotetop'>QUOTE (Medicine_Man @ May 11 2008, 09:24 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=529781)</div>
Of course it will run rich, It has no idea on how the fuel is burning without the 02 sensor. All it is going to do is meter the fueling off the MAP Sensor or AFM.. and even then it will give it more fuel to ensure it doesn't lean out..[/b]


UKDM cars never had an O2 sensor, rather a variable resistor which enabled you to adjust the mixture (or rather CO2) at idle.

Clearly neither of them do anything at any RPM other than idle.

[JoshKE]

<div class='quotetop'>QUOTE (parrot @ May 11 2008, 10:57 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=529813)</div>
Clearly neither of them do anything at any RPM other than idle.[/b]

Negative!

It makes a massive difference in a Z32 if your o2 sensors are dead...

You'll find that it mainly effects the economy of long cruises (highway driving) rather than city stuff, but when I replaced the ones in the Z I went from around 550 highway Ks (55L tank) to around 700-750ks.

I guess that doesn't answer your question on how much effect it has on a 4ag, but it obviously makes a big difference in RPM other than idle... You might be thinking of TPS parrot...

[ke70dave]

hey man, I'm almost certain that the O2 sensor is only used for constant revs, ie highway driving.

the standard O2 sense is a narrow band sensor, in short it takes approximately 10 seconds to react to changes in fuel mixtures, thus it is only used by the ecu when on the highway to make slight adjustments to the fuel map/fuel input.

for interests sake a wide band O2 sensor is a sensor that reacts effectively instantly to changes in air/fuel ratio. these are the ones you have on ecu's that "auto tune" on the fly. adaptronic etc. and are the ones that are shoved up your exhaust when dyno tuning programmable ecu's.

so i do not believe that having no O2 sensor would make any significant difference to non highway driving fuel economy.

ALTHOUGH

in many instances i have heard that not having the O2 sensor plugged in will give reduced fuel economy across the board. weather this is because the ECU is programmed to expect an input and when it doesn't receive a signal it just adds in extra fuel to be safe? or maybe for some other reason the ecu adds in fuel, I'm not sure, standardecu's use alot of variables to tweak the fuel map..since they are designed to work in such a range of environments/air temps/fuel quality..the list goes on...

so if i was you i would be inclined to just get the O2 sensor put in, it shouldn't cost much for an exhaust shop to weld it in.

[Ru-iki]

You know it will only cost about 30 bucks to put it back in if you still have the sensor. Why are we even discussing this? Yes it will help, if it was designed to have it, then put it back. Do eeeeeeeeeeeeet.

The hesitation is probably from running rich. Is it like, you jump on the gas, note changes, aceleration slowly increases at first, then builds but it just doesn't feel crisp? Probably well rich, get the sensor back in. Have a read of what it does here if you need convincing:

http://en.wikipedia.org/wiki/Oxygen_sensor


The O2 sensor is especially important if you are on a factory Toyota ECU.

[parrot]

<div class='quotetop'>QUOTE (TTZ32 driver @ May 12 2008, 12:10 AM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=529840)</div>
You might be thinking of TPS parrot...[/b]


No, the oxy sensor. Remember the 4age only has a one wire oxy sensor.

I don't even know what a Z32 is, but if it is newer, i am guessing it may have more than just one wire. I wonder what is the purpose of the extra wires on these?? I have no idea.

Perhaps in a 4AGE, the ECU only reads the oxy sensor or variable resister (VAF) below a certain amount of throttle actuation, thus at idle or highway cruising? i have a UKDM engine loom with the VAF sensor and no oxy sensor. When I wired in the oxy sensor, it made no difference at all to fuel economy.

But there have been plenty of threads around the various sites noting that the oxy sensor will only effect fuel economy at idle (i.e. traffic), or on highway cycle.

Note also it is one of the components of a functioning emissions setup, along with EFI and the cat con.

[samuel]

Last I heard, the O2 sensor only affects "lean cruise"

Which helps your ECU get the mixtures right for highway driving as previously mentioned

[verm69]

FFS... just put it in... nothing to loose, only to gain...

<div class='quotetop'>QUOTE (Ru-iki @ May 12 2008, 11:34 AM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=529913)</div>
Do eeeeeeeeeeeeet.[/b]

[slydar]

it might help if you let us know which version of 16v you have.

its not at all important on ae82/86 blue tops.

on ae92 smallport it makes a bit more of a difference i think.

nick is right, for big port, it only works on cruise (constant load/throttle position)

[Ma61Rims4Sale]

without an O2 sensor you will waste fuel.

[Nikkojoe]

I'm pretty sure the ecu requires the o2 sensor for an initial report value (to ensure its functioning ok). If it aint working, ecu would mostlikely adjust the fuel to what it thinks are much safer levels to compensate.

Multi wired o2sensors are for the self heated type (power wires to the sensor).

1 wire are just signal
2 wire are signal and exhaust temp readout (i think)
3 wire usually contain a power, signal and ground
4 wire are usually power, signal, exhaust temp and ground.

Self heated are usually used if place further away from the engine. A GZE uses a 4 wire (one for exhaust temp) as its placed on the secondaries after the flex pipe compared to a bigport single wire on the primaries.

[Dish]

Fuck me, didn't this open a can of worms.

I've got the Jap bluetop version. Was mainly just asking cause everyone I talked to said it would make barely any difference and obviously, since it was removed I've noticed a large difference. I drive to coolangatta from Victoria Point and back every tuesday, that's over 150km return. And most of the time to coomera from vic point and back, so I do quite a bit of highway driving.

Thanks everyone, might ring up the exhaust joint on friday and get it put in.

[dctrd]

<div class='quotetop'>QUOTE (Nikkojoe @ May 12 2008, 11:24 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=530273)</div>
I'm pretty sure the ecu requires the o2 sensor for an initial report value (to ensure its functioning ok). If it aint working, ecu would mostlikely adjust the fuel to what it thinks are much safer levels to compensate.

Multi wired o2sensors are for the self heated type (power wires to the sensor).

1 wire are just signal
2 wire are signal and exhaust temp readout (i think)
3 wire usually contain a power, signal and ground
4 wire are usually power, signal, exhaust temp and ground.

Self heated are usually used if place further away from the engine. A GZE uses a 4 wire (one for exhaust temp) as its placed on the secondaries after the flex pipe compared to a bigport single wire on the primaries.[/b]

Yep, i can see the ECU going into a safe, rich map if the O2 check fails on startup. This would bugger your economy/Throttle response to some degree.

Hmm, i don't think there's any exhaust temp sensing in these plugs.

The 4 wire jobbie on my bigport (from an ADM AW11) has (according to the wiring diagram):
Heater Power
Heater Ground
Signal +ve
Signal Ground

AFAIK, the 2 wire sensors are Signal and ground. I believe this gives a more reliable ground signal than the 1 wire sensors (1 wire sensors rely on grounding through the exhaust manifold).
The heated sensors get upto temp quicker and stay at a more stable temp when driving. This gives more consistent/accurate readings as O2 sensors have a fairly narrow temperature range, outside the range the accuracy goes way down.

This is stuff i've picked up from all over the place, so please correct me if i'm wrong.

[reecegze]

i run no o2 sensor in my 4agte for the safety reason of running a stock ecu for the turbo .. car makes 130kw on 9 psi , then i tested it with an o2 sensor in for the ecu and car made 134kw with less fuel dump down low.. but i continue to run no o2 sensor for safety reasons

[Nikkojoe]

<div class='quotetop'>QUOTE (Wiggles @ May 15 2008, 02:40 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=531494)</div>
Hmm, i don't think there's any exhaust temp sensing in these plugs.[/b]

The last wire on my o2 sensor plug is unused and I'm pretty sure it goes to exhaust temp on the ecu(checked it when i wired up my engine). There is an exhaust temp check lamp on the ae92map and ae101 gze cluster and there are no other sensors on the exhaust.

[dctrd]

<div class='quotetop'>QUOTE (Nikkojoe @ May 15 2008, 10:49 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=531688)</div>
There is an exhaust temp check lamp on the ae92map and ae101 gze cluster and there are no other sensors on the exhaust.[/b]

Really? That's the first i've heard of EGT sensors in a factory setup.
Any idea what the ECU does if it reads EGT too high/low?.

[Nikkojoe]

One of the wiring diagrams i found shows it, but i don't think its right. That said you might be right too but there is definately a temp lamp coming off ecu.

Perhaps its built into the function of the o2 sensor as a particular set of values?