Hey guys, this is a really silly question, but I can’t for the life of me figure out how many friggin’ oxygen sensors this car has. The Haynes manual says there is one oxygen sensor, located in the exhaust pipe. However, it looks like there is a second one in the exhaust manifold. Should I trust my eyes instead of the manual? If the sensor in the exhaust manifold is not an O2 sensor, what the heck is it? I can’t find it in my manual, nor after hours of digging around on the internet.
Anyway, the reason I’m playing with these sensors is that I got a CEL about an O2 sensor, bank 1 sensor 1 (and I should have written down the code, because I’ve forgotten it now). I got a sensor from the auto parts store, and the one they gave me was an upstream sensor which does not fit on the exhaust-pipe mounted O2 sensor (plugs are rectangular on the replacement, circular on the original).
So the question boils down to, “what should I do?” but mostly I’m wondering if there are two sensors, which to replace, and with what component?
Hopefully that all makes some sense! I’ve attached pictures of the two suspected O2 sensors. The first is the one mentioned and pictured in my Haynes manual (mounted on the exhaust). The second picture is the one in the exhaust manifold, which is not mentioned by Haynes.
Hmm, well I’m gonna pop off the O2 sensor to take a look anyway. I’ve done some cursory looks for leaks but I reckon I should get some carb cleaner and check for vacuum leaks. I’ve been putting off checking the PCV system because it’s underneath the intake manifold and sort of a pain to get to, but I know it needs to be checked. I figured that vacuum leaks, etc, would cause a lean code rather than an O2 sensor code but I am pretty much a novice still! Thanks for the advice guys.
No offense taken! She’s old, but she’s only got 60,000 miles on her, so I’m trying to keep her in good shape. 60,000 miles means, though, that a lot of maintenance that would have been done ten years ago hasn’t been done yet. I’m waiting for old, infrequently used, parts to start falling off and I don’t mind swapping them.