nwin

Saw something posted for a '95 O2 sensor problem, but I think a new generation and the addition of OBD-II came along in '96...searching found nothing on this:

'96 Honda Civic LX 5-speed in question here with 120k miles (1.6L non-VTEC).

Anyways, driving home last night, the check engine light came on. The engine didn't sound any different than it has in the past and it didn't give any indication that it was going to stall out on me. Gauges (temp is the only one I have on the car) read fine. The CEL came on while I was driving...there were no adjustments to my speed or any bumps I hit in the road between when the CEL was off and when it popped on.

I got home fine and turned the car off and tried to turn it back on. That worked fine. I checked all my fliuds, and everything seems fine.

Well, I went to Autozone, and the code it gave was P0420.

We went and checked the book that he had on it, and it gave 5 likely outcomes.

The first one was the catalytic convertor

The second was 02 sensor

The third was misfiring

the fourth and fifth I forgot. (but they were the least likely out of the 5).

Anyways, it looks like it's probably the cat or the O2 sensor...judging from the info I have found on these guys, they die in the range of 90k-120k miles...so that's probably more possible than the cat, I would assume.

Where are the two O2 sensors located at (there is one pre-cat and one post-cat)? From my old '91 civic, the catalytic convertor was underneath the body right before the muffler...however taking a look here it looks like the cat is in the front part of the engine, right behind the radiator (the reason I say this is because right on the header is what looks like a sensor, and I don't think there are any other sensors other than an O2 one pre-cat that would be on the header.

Also, I was reading another thread here that said for the pre-96+ civics that use OBD-I, that there is a way to read codes (it involved seeing how much the CEL flashed, kinda like morse code). Is there something similar I can do with my civic, and if so, how?

Sorry for all the questions, but I would like to see if it's possible to make sure I know what the problem is (which O2 sensor or the catalytic convertor, or perhaps something else I am unaware of) before I fix it or pay to have something done.

A quick last minute question-if it's the cat or the O2 sensor, is this something necessary to have fixed? I know I will need it to be done for emissions obviously, but if it's something that can potentially wait, then I might do that.

Thanks in advance, everyone.

nwin

bump