goodmpg
07-12-2021, 12:06 PM
I have a 2012 Yaris LE hatchback with manual transmission. About a month or two ago, the engine light started coming on. I didn't notice any real change in the sound or feel of the car while running, but my son hooked up an ODBII analyzer. It eventually gave us something about a 'downstream O2 sensor', so I went ahead and bought one after watching a couple of youtube videos that made it look like changing it would only take 20 minutes. My understanding is that frontstream means in front of the catalytic converter, while downstream means behind. Evidently the frontstream O2 sensor does a lot more to make sure that the engine is running properly, while the downstream sensor supposedly makes sure that the catalytic converter is doing its job.
Fast forward to today. My son and I got the front of the car up on metal ramps, and then looked underneath. We can only find a single O2 sensor under there, and it doesn't appear to be back behind the catalytic converter. Also, while the replacement we purchased has a simple electrical connector that you can get loose with a flat bladed screwdriver, the only O2 sensor we found anywhere when tracing the exhaust has a black plastic electrical cable that goes up into the metal of the car body. I used a finger to trace the electrical connector up into the hole (rubber round 'boot' cover seals it around the wire), and we can't feel any sort of similar metal plug that ours has.
What the heck? We thought this was going to be simple, and now we can't even seem to locate the downstream O2 sensor on the underside of the car!
I logged on to our local library, which has a number of online sources from Chilton, but while it has loads of technical stuff about testing the sensor on a test bed, it doesn't have a schematic, photos or anything showing the location of the downstream sensor.
Help please!
Fast forward to today. My son and I got the front of the car up on metal ramps, and then looked underneath. We can only find a single O2 sensor under there, and it doesn't appear to be back behind the catalytic converter. Also, while the replacement we purchased has a simple electrical connector that you can get loose with a flat bladed screwdriver, the only O2 sensor we found anywhere when tracing the exhaust has a black plastic electrical cable that goes up into the metal of the car body. I used a finger to trace the electrical connector up into the hole (rubber round 'boot' cover seals it around the wire), and we can't feel any sort of similar metal plug that ours has.
What the heck? We thought this was going to be simple, and now we can't even seem to locate the downstream O2 sensor on the underside of the car!
I logged on to our local library, which has a number of online sources from Chilton, but while it has loads of technical stuff about testing the sensor on a test bed, it doesn't have a schematic, photos or anything showing the location of the downstream sensor.
Help please!