Shortly after the tune up, I ran into another issue with the RSX Type S. I got the infamous Check Engine Light (CEL) that showed up on my dash.
I plugged in my OBD2 sensor and got the code P0139. Which is bank1 sensor 2 failure due to low voltage. I was considering replacing the O2 sensors anyways at it was over 100k miles, but this just forces me to do it earlier. Before I changed it, I just wanted to make sure it wasn’t anything else like a short circuit from wiring or something else.
I picked up an Autel Autolink AL519, a more modern OBD2 reader than the old one I had that just read codes. The reason for this is I wanted to get live data about the car when trouble shooting. The Autel AL519 allows me to really diagnose, by not only reading the code and resetting it, but I can also see a graph and specific numbers as I operate the vehicle.
It would seen like after testing, the voltage oscillations of the bank 1 sensor 2 was not hitting the normal readings, so it hinted at replacing the secondary sensor.
I bought a DENSO primary sensor direct from densoproducts.com as it was much cheaper than dealer prices and pretty much the same OEM unit. That’s a pro tip, you can save money by cutting the middle man out and going straight to the manufacture, you get the OEM part as well. The hard part is knowing which manufacture makes which part.
For the secondary o2 sensor, I went with an NTK sensor which I also learned is made by NGK.
The replacement of both sensors were pretty straight forward since I had the right socket, only one issue I ran into was the clearance of a breaker bar or ratchet. I ended up using an open wrench to turn the o2 sensor socket.
After resetting the code after install, it’s been about 500 miles and the CEL light has yet to return. Thank goodness! I can say that it’s fixed for now.
If you’re interested in seeing a video, you can view the install and the diagnosis in my Youtube Channel here.