O2 sensor readings from torque.

[Rakin]

Hello guys. It's my first post here, I've been browsing as a guest for quite a while now looking at the threads related to the 1NZ-FE and this forum has been quite helpful in helping me gain more knowledge about my motor.
Firstly I must confess, I do not own a Yaris but a NZT240 Premio which consists of the same 1NZ-FE powered drive-train as the Yaris 1.5L under a different sedan shell.

Okay so I've dropped in a recon 1NZ a few months back and I've been noticing recently that there is a strong smell of unburnt petrol coming out of the exhaust pipe. O2 Sensor and MAF sensor was the first thing I checked because they control the fuel loop. The O2 sensor in the Manifold had done more than 100K KMs and was completely burnt out and filled with carbon so my mechanic replaced it. Now I could not get a new one at that time (Lack of availability of the lesser common parts here) and had to settle for a recon one. Note car did not throw a CEL.
I noticed the smell was slightly less than before but still could smell it from the driving seat. I connected my OBDII ELM327 Diagnostic adapter and did a graph view of the O2 Sensor at the manifold (It's the only O2 torque would read anyways). I'm attaching the graph below, is it normal for the O2 to jump around like that? Throttle was held down at 2800RPM.

[CTScott]

That looks quite normal for 02 sensor output.

Since you can smell it in the cabin of the vehicle, I would check for exhaust leaks, particularly where the exhaust manifold connects to the exhaust pipe.

[Rakin]

Originally Posted by CTScott

That looks quite normal for 02 sensor output.

Since you can smell it in the cabin of the vehicle, I would check for exhaust leaks, particularly where the exhaust manifold connects to the exhaust pipe.

I see. I'll check for exhaust leaks first thing tomorrow. Oh and I can smell unburnt fuel from the exhaust tip as well.
Thanks.

[CTScott]

Originally Posted by Rakin

I see. I'll check for exhaust leaks first thing tomorrow. Oh and I can smell unburnt fuel from the exhaust tip as well.
Thanks.

Have you cleaned the MAF sensor? Also, if the injectors are plugged they could cause the fuel to not properly atomize and therefore not fully burn.

[Rakin]

Originally Posted by CTScott

Have you cleaned the MAF sensor? Also, if the injectors are plugged they could cause the fuel to not properly atomize and therefore not fully burn.

I changed out the MAF a month back (The old one died), I too am suspecting the injectors, but in the past when the injectors needed replacing there would be issues with acceleration or the throttle would be laggy none of which are present right now. The car runs fine except for the strong exhaust smell. Do you think I should swap out the injectors?

[CTScott]

Originally Posted by Rakin

I changed out the MAF a month back (The old one died), I too am suspecting the injectors, but in the past when the injectors needed replacing there would be issues with acceleration or the throttle would be laggy none of which are present right now. The car runs fine except for the strong exhaust smell. Do you think I should swap out the injectors?

I would say only to do so if you have an extra set on hand. Also, verify that the new MAF is the correct part number for your car. I have seen autoparts places over here sell people Tundra ones, which look identical, but have a different part number.

[dj92]

At least my Yaris has 2 O2 sensors, one pre and one post cat.
Does your car have 2 of them, too?
The 2nd one should be constant at iirc 1, if not, the cat does not work properly (spoiled, totally wrong F/A mixture, cat not heated up)

[Rakin]

I believe there is one at the manifold and one just before the cat or after the cat (Not sure). Torque only reads from the manifold sensor sadly, I'll trying to poke in a multimeter and check the other sensor.

[dj92]

Have you already consulted the list of available sensors?
Tap a few seconds on the screen to create a new instrument and check how many O2 sensors are in the list.
If there are two sensors, their values should be available via OBD.

[Rakin]

Originally Posted by dj92

Have you already consulted the list of available sensors?
Tap a few seconds on the screen to create a new instrument and check how many O2 sensors are in the list.
If there are two sensors, their values should be available via OBD.

Only one sensor available via OBD/Torque. I couldn't check the downstream sensor (I'm sure there is one), need to put the car up a lift. I'm getting a new exhuast soon anyways, is running slightly rich until then gonna be too much of an issue? ELM327 doesn't have access to all the sensors I'm led to believe.

[I_Love_My_Yaris]

Rakun, how is your fuel consumption ?

[Rakin]

Originally Posted by I_Love_My_Yaris

Rakun, how is your fuel consumption ?

~8 km/l, it's heavier than the Yaris and traffic here is really bad so no comparable data unless you're in this city. :P