hello all,
my friend is having issues with his mr2
Its a MR-S (jap import) hes getting the codes above
according to what we have read its the o2 sensor codes.
he has replaced one of the 02 sensors (with new NGK one) but still gets both codes ? should one not have gone away ???
As its the import does this make any difference is the code still the same ?
any ideas / help please
Have the codes been reset/cleared
Yes
Has "your friend" bought a ten bob one off of Fleabay? They're known to be somewhat unreliable...[emoji23]
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My friend as you well know would only get the finest lol
As you probably know, that's the heaters on both sensors on the manifold. They can be damaged just by giving them a knock or dropping them.
Advise your buddy to bite the bullet and buy a pair of Densos. Install with care.
Quote from: "ilovejapcrap"My friend as you well know would only get the finest lol
Haha! If they don't clear we'll try those spares of mine.
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Its worth checking that it was the heater circuit on the sensor side that was broken. If you have a multi-meter check the resistance of across the heater circuit, is it broken?
If it isn't, the issue may be elsewhere. Theres a couple of youtube videos, if you search checking o2 heater circuit.
Right he had checked the heater circuit and has no voltage. Ideas please ?
Don't forget it's the Mr - s model
My daily driver is an MR S. Only real difference is no main cat sensor.
Check the fuse for the heater circuit. No I don't know its number... mine was missing when I got the car. It's in the box to the left of the engine.
Good luck with the fuses, the handbook doesn't quote the O2 sensors by name [emoji23]
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here i am getting my ass in gear and registering my own account.......
so,jap mr2-s , engine management light on,scanned it using JOBD , came up with codes po135 and po155 , both the lambdas on the manifold , also did the paperclip test in the OBD port and gave the codes 21 and 28 relating to the lambda on the o/s manifold. canceled the EML light out and re sceanned showing no codes stored,also checked with the paper clips and no fault codes showing, fitted a new NTK sensor to the o/s bank , EML was out but then came back on within 3 start ups , cancelled the light again and borrowed a pair of lambda's to fit up , same result - eml light back on and showing codes po135 and po155 when scanned.
delving a little deeper - am i right in thinking that with the ignition switched on and the engine not running there should be a live at the 4 pin plug connection on both lambdas on one of the two heater circuit wires ? as i dont have a 12v live showing
i have checked the relevant fuses for conducting and theyre all working -
n/s dash fuse box -
HTR 10a
ECU IG 7.5a
ECU B 10a
n/s engine compartemtn fuse box -
ECU B1
EFI 1
HTR 40a
if a 12v live should be at the lambda plugs on one of the heater circuit pins whats stopping it from getting there ?
No joy yet pal ?
Fuses OK. That would leave the relay, I suppose.
The heater circuits in the O2 sensors have burnt out like mine, the sensor itself might still be working correctly, it just won't work the best until its up to temp - can you see any O2 readings coming from the sensors?
Quote from: "m1tch"The heater circuits in the O2 sensors have burnt out like mine, the sensor itself might still be working correctly, it just won't work the best until its up to temp - can you see any O2 readings coming from the sensors?
The same codes come up regardless of what sensors are in, even ones we know to be working ok, so that leads to an issue somewhere else in the system.
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theres no power going into the heater circuits from the 4 pin plugs. did test the resistance on the sensors - at 12v range was showing 0.01 , but regardless......if theres no power to the circuit,it wont show anything. anyone know where the relay is located , had a quick google but cant seem to come up with it
Quote from: "m1tch"The heater circuits in the O2 sensors have burnt out like mine, the sensor itself might still be working correctly, it just won't work the best until its up to temp - can you see any O2 readings coming from the sensors?
so how do you fix is it a lot of wire ?
I'm not sure if power is meant to be going to the circuit with ignition on engine off. You could try this light bulb trick:
m https://www.motor.com/magazine-summary/ ... -failures/ (https://www.motor.com/magazine-summary/diagnosing-o2-sensor-heater-circuit-failures/) m
Quote from: "lgriffiths"I'm not sure if power is meant to be going to the circuit with ignition on engine off. You could try this light bulb trick:
m https://www.motor.com/magazine-summary/ ... -failures/ (https://www.motor.com/magazine-summary/diagnosing-o2-sensor-heater-circuit-failures/) m
powers not there with the engine running either