Oxygen Sensors-02

[teamer]

Hello fellow 1UZFE owners,

Any recommendations on O2 sensors? I priced out the OEM at Lexus and they want $257 ea. A dealer mechanic friend of mine (Honda) recommended that I do not use aftermarket for risking to damage the engine control - (if the amperage ratings are different). I was also told by another to use Denso - since they are probably the ones who supplied Toyota for the factory ones.

I am leaning on Denso (cheaper), but, am not sure.

Any suggestions, advice?

Thanks!

 

[Big]

If i was you I would try to get some second hand one..(in the USA..)there are plenty of UZ's over there..would be way cheaper and original part..cheerzz

 

[gloverman]

I use Bosch units - either single wire no worries or make sure the heater wattage is correct for the four wire units. Cheers

 

[XR8tt]

02 sensors are like spark plugs.. They realy should be replaced every 60,000 or so miles.. They tend to make the car run richer as they get older.. So to a point you will save on fuel ecenomy..Esp at $$ fuel now ...

 

[stevechumo]

I believe the Bosch O2 sensors will be just fine. When they design it for the SC400, it should work for the SC400, unless it's the universal one. This is not really rocket science about the O2 sensors. I wouldn't use the used one because they might be high mileage just like yours.

 

[RedPhoenix]

What do you think of these? I wanted to replace atleast 2 of them, if not 4, Not sure about the rear 2.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160146561650&rd=1

http://cgi.ebay.com/O2-OXYGEN-SENSO...ryZ33557QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

any thoughts? they are a lot cheaper.

 

[stevechumo]

They advertise them as universal. But if they have specific instruction as which wire goes to which wire of your stock sensors, then it'll be ok. 1 important thing is you should solder the connections instead of using the provided clips. This will eliminate the unnecessary resistance and will increase the accurate reading. I've extended the wires with soldering up to 3 feet for the rear O2 sensors to fit the exhaust and there's no issue ever since.

 

[RedPhoenix]

Yep, I plan on soldering. I dont like using connectors if I dont have to. They are universal 4 wire ones, so I should be able to get them to work.

 

[RedPhoenix]

Also which ones are they? I got these 2 codes - 21 and 28

21
Main O2S & Heater Signal

28
Main O2S

Im assuming to just replace both main ones?

I just bought 2 cheap Denso ones. I want to see if they are worth a damn or not. Or even if they are REAL Denso... lol

 

[gloverman]

Guys you should never solder the signal wire of an oxygen sensor as it needs a reference air supply down the wire itself. I have discussed with tech experts who work for bosch as I use alot of bosch parts. I have soldered them in the past and had some of them fail before time. Bosch have a very clever connector which works very well. Cheers

 

[jibbby]

I never changed my O2 sensors out ever and I got a 130,000 miles on my car.. My philosophy is - if it's not broken don't fix it...

Are you sure it necessary or a good idea to change the old and original O2 sensors on 92 SC4 if you are not experiencing any problems? I've never heard of that being like spark plugs......

 

[gloverman]

As oxygen sensors age their response slows and this can lead to higher fuel consumption. People are often surprized how much of a difference new sensors can make - cheers

 

[Big]

Well thats good newz..got any..?

 

[gloverman]

sure do - I will call you again tomorrow - cheers

 

[jibbby]

Well, how about this - When the 02 sensors begin to age and run the engine rich won't the smart function of the ECU adjust accordingly or even better how about a piggyback ECU tune to compensate? Or are the computer reads off too for the tuning aswell with the O2 sensors being old and bad too?

Hmmmm?

 

[stevechumo]

I don't think the ECU is ever smart...LOL. Actually, the sensors feed the info to the ECU such as too much fuel or less fuel. The ECU has a preset of map that adjusts accordingly to that info. When the sensors are dirty, it gives false info that makes the ECU change. There's a lot of info on how the O2 sensors work, so you might google for it, especially on www.howstuffworks.com

I don't know what the people at Bosch say, but I believe soldering is a good method to connect the wires. It's because I installed several piggy back ECUs and most of them recommending soldering. I used to measure the resistance between a straight wire, a clipped wire, and a soldered wire. The clipped one has more resistance, which changes the reading. A good soldered one usually has the same resistance as the straight one. This is critical when extending the wire, or connecting when the wire is supposed to be straight. On my SC, I extended all the MAF wires and the O2 sensors wires with no problem with soldering.

The exception might be the sparkplug wires, but not the O2 wires. The sparkplug wires have different electric and static area around the wires with specific resistance.

My friend (JamesN) on this forum just extended and soldered all the wires from the fuse box a few months ago. His car runs just normal.

 

[jibbby]

Yeah Steve I think you are right... I just thought maybe you could manipulate the ECU to overrun the reads coming from the O2 sensors if they were slightly a miss...

 

[gloverman]

When we fit Aftermarket ecus we solder everything except the wire connected directly to the oxygen sensor. This wire is usually a stainless steel wire and crap to solder anyway.
I have fitted and tuned Apex-1 AFC and watched as the factory ecu overrides all the changes that I make. Sometimes very fast too. These devices often only work when the ECU goes into open loop.

Cheers

 

[jibbby]

Gloverman not to disagree with ya but -

APEXI safc II's will hold a setting on the factory 1uz.. ... I've personally held a slighty lean mix for one year exactly in years past with my Apexi...I then had to go back and tune again for a richer fuel mix when I increased the nitrous shot and was pleasantly suprised it held for all that time.... I checked the dyno sheet on both and they were identical year to year. As you may know the stock factory ECU settings are set to run slightly rich for safety......No ECU self adjusting on my watch... I am very confident that my Apexi SAFC II piggy back ECU will hold a tune setting.....

 

[gloverman]

Different ECUs do different things. I have an Altezza (IS200 or sportcross) which does not trim off my settings at low revs or high revs. I have done some (not all) hondas and they trim it straight back out or back in at low revs. Nissans take a little bit of change then trim it out. In open loop it will hold as the oxygen sensor is not used. Some ECUs ran fine without oxygen sensors connected and others are completely crap. I had an EVO 4 lancer which went extremely rich when the oxygen sensor failed. Cheers