I bought a 2008 Nissan Versa LS last month. It has 235,500 kilometres on it but the engine and transmission run quite well. Last week, the “Service Engine Soon” light came on when I started it up after work. The fuel tank was almost empty so I filled it up and cleaned out the gas cap and o-ring but the warning light is still running.
So I bought a Millennium 50 port scanner and plugged it into the OBDII and got DTC p1421. I did a quick O2 sensor scan with the device and I can see and collect data for one of the O2 sensors but not the other.
Is this a indicator that the sensor that isn’t readable is damaged and the cause of the warning light? To experts and gurus, this might be obvious, but two different websites that appear to be reputable tell me two different things.
One site claimes it’s the air filter, while the other claims it’s a an issue with the ECU among other things. I’m not a mechanic so I don’t know.
Is there an issue with buying a used Nissan-built O2 sensor on eBay?
Thanks in advance.
I tried to run tests on the O2 sensors with the port scanner, Bank 1-Sensor 1 is unable to be read by the scanner. Bank1-Sensor2 appears to be fine. That is making me suspicious.
I checked the air filter and the filter is new. It appears that the dealership replaced it.
My Dad wonders if the warning light is on because of a oil change counter not being reset at the last oil change. He thinks that the engine’s computer might be warning that the engine is overdue for a oil change, even though it was changed a few months ago. Is that a possibility?