HT Chaplain

Im using a pr3 and it requires a 2nd o2 sensor. the reason im using a pr3 is because im putting a b18c in a crx. the injectors and dist. are obd0 as well. i have a skunk2 intake manifold to not worry about the butterflies. basically its just a bigger b16a. anyways where would i put the 2nd o2 sensor? the only one on the engine is before the cat.

Newman

Get the upper part of the exhaust manifold from a 1st gen B16A. It has two O2 bungs on there specifically for the PR3 ECU. Most people just throw those away so finding one shouldn't be too hard. Otherwise, you can just get a nut from the hardware store that fits onto an O2 sensor (I can't remember the exact size off the top of my head) and weld it onto the exhaust manifold or header, and drill out the hole, and use that as your 2nd O2 bung.

pills_PMD

http://www.hondata.com/techo2problem.html

that may be of some help

Hybrid Invasion

interesting question, my b16 manifold has an o2 sensor with the plug running off of it to plug to the wire harness, then it has this thing right next to it with a wire that looks like it was cut. its basically right next to the first o2 sensor and the end of it is flat, theres another one of these on the edge of the downpipe right where the cat is connected to it, and i dont know if they are o2 sensors or something else, but if so, why don't at least one more of them have a plug to plug the second o2 sensor up to it? I dont understand. Btw, I just did this swap in a 90 CRX, and was wondering the exact same thing.

Hybrid Invasion

bump

GsTeg90

i have the same situation soon to do the swap a b18c into a 90 teg "non obd"

using a pr3 . the ecu needs 2 o2 sensors but the engine only has one. i have dc headers and only one bunk.. is is a must to add another hole?

Hybrid Invasion

bumpx2

Hybrid Invasion

bumpx3

Newman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GsTeg90 &raquo;</TD></TR><TR><TD CLASS="quote">i have the same situation soon to do the swap a b18c into a 90 teg "non obd"

using a pr3 . the ecu needs 2 o2 sensors but the engine only has one. i have dc headers and only one bunk.. is is a must to add another hole?</TD></TR></TABLE>

Yes. What I did to my CRX way back when (back in 97 ) when I had LS/VTEC, I still used my LS header, but it only had 1 O2 bung down on the downpipe, next to the cat. The PR3 ECU didn't like that and the car ran like **** since the O2 wasn't getting hot enough. What I did was I went to the hardware store, found 2 nuts that screwed into the O2 sensor, welded them onto the primary, drilled out the holes, and sprayed it with high-temp silver paint to match the header and so that it wouldn't rust, and it looked like something that DC would've done to their header. Plugged the 2 O2 sensors in there and ran it to the PR3 ECU and it drove perfect. The O2 bung that I had on the downpipe, I actually used that as a dedicated O2 going directly to an A/F meter, but you can just put a bolt in there to cap it.

Hybrid Invasion

isnt there just a straightforward website on how to wire for a second o2 sensor? I know nothing about the b16 exhaust mani I have, it looks like there's 3 o2 sensors on it, but that doesnt seem right. on the exhaust mani part, there is an o2 sensor with a plug running from it, then theres another o2 sensor-like thing sticking out of the mani, but its flat on the end of it and only has 1 wire coming off of it that has no plug on the end of that wire; the wire looks like it was cut. Then theres another one of these flat metal o2 sensor-like looking things, but its flat as well on the end and only has that one wire running out of the dead center of it with yet no plug running from the end of the wire to hook up to the wire harness. Can anybody tell me what the hell those are, and how to wire for a second o2 sensor and do it right?

Hybrid Invasion

bump

Newman

Primary O2 sensor goes to C16 on your PR3.
Secondary O2 sensor goes to C8 on your PR3.

Both are 1-wire O2 sensors, so just run a shielded wire directly from the O2 sensor (make it a good connection, ie solder) and run it directly to ECU. Both O2 sensors are the same and relatively in the same location on the upper part of the exhaust manifold. Therefore, it doesn't matter which O2 sensor (since both are the same 1-wire O2) you wire up into your ECU, but do it into those 2 locations above.

HT Chaplain

It looks like im just going to get my pr3 reprogrammed at gbrtuning.com so i only have to run 1 o2 sensor. plus im getting my ecu mapped for my mods as well. especially with the skunk2 manifold i heard if you dont get the ecu mapped its weak of the line. 150$ is what there charging

Hybrid Invasion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Newman &raquo;</TD></TR><TR><TD CLASS="quote">Primary O2 sensor goes to C16 on your PR3.
Secondary O2 sensor goes to C8 on your PR3.

Both are 1-wire O2 sensors, so just run a shielded wire directly from the O2 sensor (make it a good connection, ie solder) and run it directly to ECU. Both O2 sensors are the same and relatively in the same location on the upper part of the exhaust manifold. Therefore, it doesn't matter which O2 sensor (since both are the same 1-wire O2) you wire up into your ECU, but do it into those 2 locations above.

</TD></TR></TABLE>wow, and i just NOW find out how retarded I am... so i'm guessing since my friend had this motor in his 92 civic hatch that someone drilled a hole in the exhaust mani and added an o2 sensor, then added a plug at the end of it because i guess on the obd1 harness, theres supposed to be a plug that it plugs into the engine harness with, huh....
I think this is the most info i've received about this question. Thanks for a straightforward answer good times
Now all I have to do is find shielded wire and two connectors.....

Hybrid Invasion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Newman &raquo;</TD></TR><TR><TD CLASS="quote"> Both O2 sensors are the same and relatively in the same location on the upper part of the exhaust manifold. Therefore, it doesn't matter which O2 sensor (since both are the same 1-wire O2) you wire up into your ECU, but do it into those 2 locations above.

</TD></TR></TABLE>now see, there is one o2 sensor on the upper exhaust manifold part, and one on the downpipe, right before it flanges to the cat. Anybody else have an o2 sensor there?

redworm

if you use the b16 header on a b18c will you lose power, or are they exactly the same size?