Oxygen Sensor - Toyota Nation Forum : Toyota Car and Truck Forums

Punisher · 12-05-2003, 03:36 AM

What does the Oxy sensor (on the exhaust manifold) actually do on the 4A-F engine?

What can be symptons of a dead Oxy sensor on the 4A-F..

I should say that mine is dead.. It's the factory sensor though so there ya go.. But anyway just wondering exactly what it does since the 4A-F is carburated and if I'll actually get any performance back when I replace it.

I noticed it was dead when installing my Air/Fuel mixture gauge

lol.. I am hoping that with the air/fuel mixture gauge in place I can actually tune the idle screw on the carburator to get the right mixture so I can stop running lean or rich.. It's hard to fine tune it by just turning the damn screw and going for a drive.

Maybe the reason my car stutters likes it's going to stall when I go full throttle, before it'll pick up and take off is because the Oxy sensor is dead?

RedruM · 12-05-2003, 11:12 AM

ut cant hurt to change the o2 sensor anyways

Flashmn · 12-05-2003, 11:28 AM

I wonder what it does... mine didnt have a o2 sensor

Punisher · 12-05-2003, 08:33 PM

WOW.. all i can say is wow.. well now I can actually go WOT with out it stuttering.. so the O2 sensor was the problem.. that and it seems to really take the fuck off on the tach now.. i'll get a better idea when all this snow gets off the streets and i can whip my rolla around..

TRDragoon · 12-05-2003, 08:46 PM

you replaced it already???

did you get the OEM one or aftermarket ones?

Punisher · 12-05-2003, 09:05 PM

The original has been in there for a 114K.. I found it was dead last night.. so I went to get a Borg/Warner one today but no one had them in stock today and I ended up getting a Bosch universal for like 30 bux at autozone..

RedruM · 12-05-2003, 11:51 PM

i think i should change mine

car dont really drive so nice lately

Punisher · 12-05-2003, 11:53 PM

when I started to get this stuttering and what not after I did my mods I was thinking it might be the oxy sensor but no one wanted to agree with me on it...so i figured it was somethin else

Flashmn · 12-06-2003, 03:24 AM

Did you look where the O2 sensor gets plugged in?

Punisher · 12-06-2003, 01:10 PM

Um.. yea.. on the stock exhaust manifold it got plugged in the side of the manifold.. because they are 4-1 manifolds.. on my new manifold which is 4-2-1 it gets plugged in on the front of the manifold on the one pipe..

Flashmn · 12-06-2003, 02:01 PM

No I mean where wires go, not where its placed in the exhaust ;D

Punisher · 12-06-2003, 02:25 PM

rofl.. no I don't know.. it just goes off into the wire loom for a crapload of other engine controls.. i will look in my toyota repair manual though.. I know it goes to that small diagnostics box on the driver-side strut well.

hopeful · 12-07-2003, 11:18 AM

O2 sensor on a carb'd car... maybe its just a diagnostics tool on the car rather than the ecu relying on it for what fuel the car needs. Possibly if you were running too rich or something it would set off a code...?

Xenon · 12-07-2003, 11:36 AM

I know when my O2 sesor crapped out on my I got a Check Engine Light!

Punisher · 12-07-2003, 01:22 PM

Hmm i don't know what to say really.. i don't know what it does.. except maybe has some input on how the choke responds.. Since it's an electric choke it can close/open the choke to increase or decrease air flow before the throttle choke.. so it could richen/lean it up I suppose...