NeilAgg

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

ezone

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

NeilAgg

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.

ezone

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

NeilAgg

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

ezone

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