St184 o2 problem

[twisted-cv]

Ive got a st184 celica with a 5sfe with a 3sge head on it Ive done away with the old manifold with the cat con/ and fitted extractors. with this setup i was getting closed loop all the time so I fitted a heated o2 sensor three wire out of a ef ford. that was great for two days. now i have temp gauge reading full blast and 12v coming out of the sensor wire + a code 52 knock sensor??? does anyone know if a ford o2 sensor would blow the shit out of the ecu? any help would be appreciated.

[DunkyMonkey]

i dunno about the ford sensor, but toyota use either a 1 wire or a 4 wire O2 sensor, i have a ST184 that had a 5sfe and i have a gen III 3sge in it now, so i have seen my fair share of problems, especially with my O2 sensor as i have a mazda one on mine car at the moment, so i don't know why your only ave 3 wires, i'll just assume that the sensor is an earth like the single wire ones. but unless you have hooked up the sensor wrong i can see a concievable way an O2 sensor can crap with your ECU. maybe if you share how you wired it up, with more then the single wire ones you need to have a +12V ~for about 30seconds~, ground(heater), ground(sensor) and the last wire is for the ECU it should also be sheilded, this is how you know its the sensor wire, as mazda and toyota unfortunately for me don't share the same colour wiring.... oh well.

PS you know you can run the car with out an O2 sensor the economy will go down and the car will run rich, i might suggest you unhook the sensor and see if you have done damage to the ecu, also remember that you must rest the ECU by pulling the EFI fuse for 30seconds to rest the memory in the ecu.

good luck with it
-Dunky

[mikie_121]

My O2 sensor blew on my st162 (4 wire) and autopro found me one for $80. Maybe get a proper replacement, instead of borrowing from other cars.
I believe the 4 wire is self heated to give a much faster and more accurate reading, until the exhaust gasses take over.
So two wires for heating the sensor, and 2 go to the ECU. I'm not sure if this is correct but it's what I could make of it.
What ECU are you running with the engine? There should be a stock O2 sensor made for the ECU. Worst case - go to a wrecker and grab a sensor from there to test.

[twisted-cv]

Thanks for your helpful hints guys. I think I mayhave found the problem I disconected the whole engine harness and found 1 the oxygen sensor wire had a broken!! 2 a broken single earth wire to the ecu. I haven't tried it yet but I am hoping this will fix all my problems.
As far as my ford o2 sensor It has one 12+ to the heater -1 earth and the third wire to the ecu. But Ive just got the heater wired to 12v key on?? Is this too much ??Im sure the ford o2 sensor when operrating has max pulse of 500mv like the ome toyota oridgie o2.. Dose any one know where I can get my hands on a toyota workshop manual for the st184 with engine diagrams????
wihttp://www.toymods.net/forums/showthread.php?t=2126re

[mikie_121]

I have a workshop manual for all celicas from 86 to 98ish (I can't remember the exact date), with all the wiring diagrams for all the engines in that era. Give me specific years and I'll scan them and post them.
I had to order the book (took about a week to come) though Autopro.