- Jul 15, 2018
- illinois, usa
Yes, it is reading rich from your numbers. Wide band are normally install upstream or 1 st O2 in some cars.
0.7V on the upstream o2 is also reporting a rich condition. It’s trying to compensate by the -15% fuel trims you see. I would look at the engine, whether that be a MAP/MAF issue, or uncontrollable purge, excessive fuel pressure, a leaking fuel injector or a mechanical issue
If your cat needs that it will be brought on by an engine which is not performing well.Would cat cleaner help the situation ?
In closed loop operation, the upstream sensor should alternate high and low fairly quickly. The downstream, once the catalytic converter is hot, should remain fairly stable unless you have fuel deceleration shutoff in which case it’ll go full lean (low voltage) when coasting.So what should the relation of OS211 and OS212 should be. What is considered ideal ?
The car is a 15 years old Daihatsu Sirion 1000cc with 60.000 miles on the clock.In closed loop operation, the upstream sensor should alternate high and low fairly quickly. The downstream, once the catalytic converter is hot, should remain fairly stable unless you have fuel deceleration shutoff in which case it’ll go full lean (low voltage) when coasting.
Depending on your mileage, I’d say start with throwing some O2 sensors at it. At ~90k on my Dodge Caliber I started noticing really poor fuel economy not matter how nicely I drove, like 20mpg out of a 2 liter 4 cylinder. Never set any codes though, and all emissions system monitors were set. Replaced the upstream O2 sensor with a new NTK and my fuel economy immediately jumped up to a more reasonable ~25mpg.
Can you find them on the schematics ?1. Purge valve is part of the emissions system and can be found in different places, but they have to connected to the intake or close by to the throttle body. So pick any line and follow it backwards to where it connects to a valve.
2. MAP sensor is connected to the intake in some cases very close to the throttle body
3. Fuel pressure regular close to or at fuel rail w/ vacuum hose and a return gas line to the tank
Well if you go back you can find everything about the car:The only item in the schematics is the O2 sensor. Very little info!
Judging from the range or the reading my O2 Sensor seems to be narrow band.I don't know ................. looking at all that has been said here I think there is simply too many unknowns mentioned.
I would suggest let the thing sit overnight and cool down completely.
Switch on ignition without starting the engine, and set up logging of the O2 sensor voltage.
Now start the engine and allow it to idle for about 2 minutes without touching the throttle at all.
Stop logging and lets have a look at the response/abilities of the ECU and O2 output logged there ..............
Also - is that an actual O2 or a wideband A/F sensor?