Rep Power: 0

Hello:

I have searched the Internet to no avail.
I can't seem to find the upstream O2 sensor on a 2004 Honda Civic Si.
Can someone please give me some direction on where it is?

Thanks,
Neil

 
Rep Power: 518

You should post your location (I already know) and engine, because the Si in Canada is the same as a USA EX 1.7.

The USA Si is a 2.0 hatchback.

It's not on the internet, it's on your car.
You gotta get under it to find it.

Upstream/primary/first/front/B1S1 (it's an A/F sensor) is in the front of cat.
Not the one stuck in the middle of the cat, that's the downstream/rear/secondary/etc. sensor.

HTH

 
Rep Power: 0

I did not realize that there was more than one version of the car.
Thanks for clarifying.

I am in the US so I have the 2.0 hatchback.


I checked the Internet, I checked the engine bay, I looked under the car, I thought I looked everywhere

OK, now I found it. Thanks for the info! All the info I found on the Internet told me it should be on the back, side, or under the engine. I never looked that far back on the exhaust pipe.

 
Rep Power: 518

Man, I'd swear your location wasn't in the profile box when I wrote the first reply.

 
Rep Power: 0

It wasn't. I added it based on your suggestion.

 
Rep Power: 518

Ah ok, I thought it was me "I can't read--AGAIN!" LOL