About 6 months ago I bought a 98 civic ex from a friend of a friend (I know stupid idea). The car has a jdm d15b swap with the P2P ecu. A few days ago I went to pass deq and I failed because my 2nd o2 sensor was not working correctly. Upon closer inspection some genius spliced both o2 sensors together so both sensors were not giving correct readings to the ecu. My question is... how do I pass deq like this?

 

You don't.

 

Lets put it this way. What can I do to pass the emissions test. My state does not have under the hood visual test. What can I do to the ecu and/or wiring harness to be able to pass it. I really hope its possible... If not I just threw my money away.

 

Fix the wiring, disconnnect the secondary O2 from the primary and wire it correctly.

 

Fix the wiring so the primary and secondary O2 sensors are on their own circuits like they're supposed to be.

Before you do that, try running a spark plug defouler and see if that solves your problem. You can get them from your local parts store, and they're cheap.

 

Been said twice, get it done. You'll find your answer on how to wire in the secondary o2 sensor on ffsquad

 

I cannot wire the 2 o2 sensors seperatly because the ecu only supports 1 sensor... Where do I go from here?

EDIT: The splicing wiring problem is fixed. I know have 1 fully functional o2 sensor but cannot plug in the second to the ecu.

 

If it's a JDM ECU, they only look for one O2 sensor. Than disconnect the second O2 sensor remove it and thread a plug into the secondary O2 bung.

If it's required for emissions testing, you're kinda screwed

Edit: P2P ecu should be USDM and does read, require 2 O2 sensors

 

Uh, what? The P2P ECU is the 96-00 EX ECU. If you have a JDM ECU, then their scanner wouldn't even be able to connect to the ECU. If you failed because your O2 sensor wasn't reading properly, then they obviously could connect and communicate with your ECU, which means it isn't JDM, which means that it does in fact support a secondary O2 sensor. You're saying things that don't add up.

 

As you guys can tell i'm pretty much a complete noob in these kind of things. So what we have figured out is that I have a stock ecu and a jdm d15b. Everone seems to think that I can plug the second o2 sensor right in and it should work?

 

Follow this link, it's the parts breakdown for a 98 Civic Ex exhaust system.
http://www.hondapartscheap.com/auto-...5-speed-manual

With that said, passenger side floor pan should have a connector, like in the diagram, to connect your secondary O2 sensor

Item #27 is your secondary O2 sensor, connector should be close to the back of the catalytic converter on the passenger side.

 

The secondary O2 to ecu connector on an EX is under the center console.

 

There you go OP, exact location for you to look

 

Ok thanks everyone. First I will have to put the o2 sensor back in then il try to plug it in.

 

Assuming that some half-wit didn't cut the wires, yes, you should be able to plug it in and be fine. If some shade tree mechanic thought it would be a good idea to cut the wires, though, you'll need to run wires for your secondary O2 sensor.

 

I just took a look at it and both 5 and 6 on the A connector for the sensors are intact and nothing seems to be cut. This is a good sign yes?

 

Yes, but did you locate the O2 sensor plug under the center console? That's what you should be looking for, if it's intact, then you just need to plug the correct O2 sensor in and your done

 

Going to look for it now. I haven't tried to find it yet. I just assume the previous owners had SOME common sense.

 

Is that the o2 sensor plug? (Attached images)

 

I'm 99% sure that is what you're looking for, O2 sensor has a grommet on it where it passes through the floor pan.

 

Read your OP thread and tell me what ecu you have again.

 

Lol easy with the insults. Everyone has to start somewhere. I know i'm a complete noob but im learning. I have a P2P ecu. Stock ecu for an EX.

 

if the wire colors on the plug are wht/red, grn/blk, blk/wht and blk/yel, you found it.

 

Plug the secondary into the cat converter.

 

I know I'm usually the resident ***, but you need to take a step back man. My assholeishness has a purpose - you just seem to be raging.

Side note: Holy ****, "assholeishness" is actually a word