Fitting extractors, what about the oxy sensor?

[Ta2272]

Hey guys this is actually regarding my Pulsar not my ta22, i was condidering putting a set of extractors on it, (sr20) one thing that popped up is, would the extractors have a place for the oxygen sensor or would i have to just fit it somwere else, and if this is done will it read falsly at all, and give me a poor mixture.

Thanks guys

Jason

[oldcorollas]

if it's three or four wire, it kinda doesn't matter where it is...
if it is 1 or 2 wire, then it needs to stay around the stock distance from the head so it stays hot enough to give good readings.

[fade-e]

why dont you drill a hole, weld a bolt and screw the sensor back in... best place to drill would be where the extractors meet up...

[YelloRolla]

decent extractors ought to have a location for it. Like Stu said, depending on type of oxy sensor, it may not matter.

Oxy sensor nuts are available - the thread size is M18 x 1.5 from memory.

[oldcorollas]

yup, M18x1.5. you should be able to get a bung from any decent exhaust place for under $10.. and then just weld the bugger in so it seals too easy

[sam-131]

umm i have a mate who owns an exhust shop and well from wat i saw in the order sheets was that there options when ordering a set of extrators (ie epa gear) just make sure you tell them you want one with a oxy sencer place/hole and he'll just cross out a box

if you dont mind me asking what are you getting 4-1/4-2-1?

[YelloRolla]

yes Stu. I bought a bung from Liverpool exhaust in Syd for $5. It wasn't even worth trying ot buy a nut and turn it down so it looked decent.

[sideshow]

nissans run a 3 wire sensor
so one wire is power to heat it up

but for not probs down the track fit it as close as u can to orig spot
then u know u cant go wrong

nissans run shit of the mark if oxy sensor is not working

[o_man_ra23]

ALWAYS have the oxy sensor after all pipes have collected, otherwise if one cyl is slightly worn it will read incorrect, and either destroy that cyl, or the other 3 from wrong fuelling. Having after the collector will average out things, might run a bit rough, but shouldnt destroy anything, and will still give early warning of engine wear.

But yeah, any decent set of extractors which are designed as OEM replacement should have ox sensor hole, and with the 3 wire, it dont matter where it goes(as long as its after the collector)

Cheers, Owen

[oldcorollas]

fwiw, i ran my sensor (4 wire bosch) just behind the gearbox at the collector (5ft or so from head) and response was still fast and never had issues with sensor being to cold...

[EVOSTi]

i dont know that the oxy sensor on one cylinder only WOULD potentially destroy the engine. from my understanding, the oxy sensor mainly is in effect when the engine is cruising/light throttle? could be wrong but that was my understanding. ive seen a few cars with them on one cylinder (mainly 4age's) and they didnt APPEAR to have problems, i also ran my car like this (but had a haltech).

also with rwd 4ages with the trd style extractors, the collector is pretty far down, much farther than standard, woldnt the sensor have little effect back that far? wouldnt it be better to have it on one cylinder near the head than way back down the exhaust where it will be cooler anyway?

[Hen]

It shouldn't matter about distance from the head if you are running a 3 or 4 wire oxy sensor. They heat themselves up.

My thoughts are that they are best fitted after all pipes join, but I doubt it would really make a huge difference to run it off one cylinder.

Hen

[o_man_ra23]

evo, read stu's post, the 3 wire ones are self heating and dont matter where they are down the track. A good setup should always be reading the ox sensor to continually adjust, as a fully rich mixture will be no good for power, and a lean mixture can be potentially fatal. So really, the ox sensor should be used by the computer as a feedback loop continually fine tuning the mixture. Check out some automatic control theory, itll give you much better understanding on what an efi computer does.

Cheers, Owen

[EVOSTi]

i know that 3/4 wire sensors are heated, what i was getting at and should have made clearer is that oxy sensors such as that on a 4age are single wire, and when using the trd style extractors, they would have to be positioned pretty far back if you want to get a reading from all cylinders. so in THIS instance it would be better to just go off one cylinder, right?

[o_man_ra23]

as stated by sideshow, the nissans run a 3 wire, heated.

Cheers, Owen