Hi ,
I just have quick question. Opel/Vauxhall Astra H model 1.4l Ecotec engine with 120k miles.
My oxygen sensor before catalytic converter seems to make issue on my car. On OBD 2 shows that it fluctuate between .1 and .9 V.
When I unplug the sensor car idles smoothly without hesitation.
Can sensor be faulty even if it shows good data on OBD2 ?
There is no check engine light.
Thanks !
When I unplug the sensor car idles smoothly without hesitation... Can sensor be faulty even if it shows good data on OBD2 ?
possibly, but when you unplug it, the computer stops using ALL sensor data, so it doesn't really help you.
Rough idle is most often vacuum leaks, dirty MAF, etc.
https://www.youtube.com/watch?v=NWCKvU2FmDc
Opel/Vauxhall Astra
You need to post the model year per the forum instructions please.
@imperator Yes sure, 2006 is the year. I read that on the internet. Also I noticed that car stays in open loop when unplugged. Well, I could expect that since it uses O2 sensor to go to closed loop. I plugged the sensor in and it starts idling rough when sensor starts heating up and showing data.
as I said, it uses many sensors in closed loop. What is your MAF value in grams/second at idle?
Do you have a clean air filter in there? Have you inspected the throttle body as in the video I posted?
@imperator Hi, sorry for late response. Yes , I did everything in a video , it was one of the first things I did.
It shows 2.9-3.5 grams/s. Also I noticed that on OBD2 maf sensor shows erratic fluctuating reading, up and down. I saw on other yt videos that ot should be steady line. Both throttle and maf sensors are jumping up and down. I assume that ECU is failing to adjust on closed loop.
I'm guessing this is with a cold engine. Wait until it warms up and the RPM settles down. keep an eye on the engine temperature too.