Nick's 2GR-FE Trackday Weapon Swap!

[thomp1983]

If there lambda sensors they won't clear the codes they work on the wrong voltage scale so the ecu will be tripping the light as it's receiving the wrong signal

[Paul Woods]

Correct, as i've said above, you cannot use O2 sensors in place of AFR sensors, they are wired totally differently and return 0-1v compared to 3-3.4v

I get my AFR sensors from Marc in the US as they work out the cheapest that way for the genuine part.

[thomp1983]

If your desperate to get a pass then fitting a cat should get your emissions down to non cat test levels

[Monkeyra]

I keep forgetting there's a difference! So just for my own benefit in understanding all of this, the only difference between a 4-wire O2/Lambda sensor and a 4-wire AFR sensor will be the gubbins inside the sensor itself?

[Monkeyra]

I just want to throw this out here in case others have had this issue. I've been in touch with Marc (Gouky) to get some new AFR sensors, and he thinks I've more chance of winning the lottery than both my AFR sensors being dead. So, one question, how are these sensors earthed? Marc think it's a grounding issue. I've continuity checked the ground (signal -) which do indeed go back to the ECU. Are there any other grounds I should be aware of?

As a further aside, I checked the resistance across the heater, and with my multimeter set ok 2k, I got a reading of 0.003, which I **think** means the heaters are possibly actually ok?

I'm trying to exhaust every avenue before I splash the cash! Moving house this weekend so it's an expense I could do without.

[snowtigger]

Just a random thought is it the ecu that has a problem, I would wait till after you've moved and every thing has settled down as the stress is terrible moving house.

[thomp1983]

Options as far as i can see are either remove them and see if chris wood or another 2gr owner will test them on there engine.

Rewire them with new wire runs from the sensors straight to the ecu to make sure there's not an issue in the loom.

Afaik they should be a pair of wires for the heater circuit then a sensor earth and signal wire

[Monkeyra]

Options as far as i can see are either remove them and see if chris wood or another 2gr owner will test them on there engine.

That is a good idea my friend. Would prove beyond doubt if the issue is my end or not.

[Paul Woods]

Ok so this is how both types of sensor are wired.....



The sensor on the left is AFR, three of its wires run directly to the ECU, the only wire you need to connect is a 12v relay driven power supply to the one wire that is not going to the ECU, there are no other earths or wires to connect for the AFR sensors.

On the right is a simple O2 sensor, it has two wires going to the ECU, one is the OX signal, the other is the heater control, the other two are ground and 12v power, even with O2 sensors the ground wire is usually taken care of by the ECU sensor ground on E1 or E2, so even they only need a power feed to work.

On a 2gr you do not connect up the secondary O2 sensors, not needed.
Mk3 O2 sensors will not work in place of AFR sensors.
The operating voltage signals between these two types of sensors are completely different.

If you are 100% sure there is continuity from all three AFR wires and the ECU, and you have a good power source supplying them then it only leaves the sensors as faulty or an ECU issue, maybe you've missed an ignition feed there.... double check whatever notes you've been following.

Hope that helps.

[Monkeyra]

Well, sometime later, I've an update. I sent off my existing AFR's for testing and they were confirmed dead. So ordered two new ones from the states which I finally found time to fit today. Running the car today, it's stuck in open loop (thus throwing me code errors). Any pointers on what I should be looking for to fix this? I've no idea if I had this error previously as I've only just found the function on my obdii reader.