Does anyone have a write up on the best way to replace the upstream o2 sensor on gen2? The one located on the manifold, I did the job once before but it took me 2 hours and I'm sure theres a better way but I didn't have time to research at the time. Posted via the PriusChat mobile app.
I take it you did all the removal for access shown in this excerpt from the Repair Manual (attached)? That includes wipers and their motors, the cowl and the inverter? Ugh... Maybe you could just reach it from below??
That sounds like just as much work but possibly allowing more space to remove and install the sensor. I went from below when I changed it and removed the transaxle. Posted via the PriusChat mobile app.
Oh wow! Transaxle removal has got to be more involved. I just found this on Amazon, not sure if it's 3rd gen, let alone 2nd gen compatible, but have a hunch it is. Would need to research more: FWIW, reading through the 3rd gen instruction, it's just wipers/motors and cowl, not the inverter as well. Third gen socket is indicated as "SST: 09224-00010", the same as second gen. Another contender:
Hi im looking into replacing the upstream o2 sensor and was wondering if you could provide any helpful advice? I just bought an 07 with 265K and it is getting about 35mpg. I think the bad up stream o2 sensor is causing the bad fuel economy. its also keeping it from passing emissions.
Buy the thin walled socket (many claim to be, and never are), or grind down one that is too fat. Went from underneath and it was off easily, almost like it was hand tightened. Best to buy the upstream A/F sensor at the dealer or the Denso equivalent, many aftermarket won't work. As mentioned in another thread, try Schley product number 66750B (with a B at the end), which is a thinner walled version. After researching a bunch of sockets at various price points, the above product stood out as being the best off the shelf option at a price point I can't say I was happy with, but then I don't have access to a bench grinder. This socket worked perfectly for my application.
26 dollars is a little much, but if it straight up works it's not a bad price. I have paid way more for a tool when I had to. You can always resell it here when your done. You need that tool when your cat gets stolen and you DIY replace.
+1 for the Schley 66750B, not removing the inverter and accessing the O2 sensor from below the car. I tried the tekton socket but it does not fit inside the shield off the sensor only the 66750B does. I do all of the work on all of my cars, Took about an hour and a half in total. Cowel goes quick with an electric impact gun, the O2 sensor for 16 years and 182000 mi came off pretty easily, just warm up the engine first so the exhaust pipe expands. I had codes p0031 and p2237, this fixed both.
I did it from the top and it is a bch. Hardest part was unplugging the harness because I couldn't figure out how the clip worked. Almost broke it. Second hardest part was removing the sensor. I had to buy the thin walled socket and it took me forever to get enough torque with a ratchet to finally get it broke free.
