First things first, the problem.

Under partial throttle the car hesitates, bogs and in general runs flat, but only under partial throttle. If I floor it, or give it more gas it takes off like it should. This is really starting to get annoying because I can't hold a steady speed.


Also, the car will pop, or backfire when I get off the gas and then step on the gas again. since I have to constantly step on the gas and then get off it again, the car pops and backfires frequently. I shouldn't really call it a backfire but it's kinda like that.

After doing some research I found that this is likely due to the 02 sensors, damn the pr3/pw0 ECU and requiring 2 o2's, anyway back to the possible solutions.

Possible solutions that I have read.

#1 - Reverse the pins in the ECU, take C8 put it into C16 and vice versa.


#2 - Reverse the o2 sensors in the header. I don't see how this would work because all I am doing is reversing the 02 sensors, but how is that going to make a difference?

# 3 - Take both 02 sensors out and the car will run in the open lop mode, but I will get poor gas mileage.

# 4 - Run the car with one o2 sensor.

# 5 - Get the ECU chipped to run one o2 but this is not an option, I would love to send the ECU out but I can't lose the car for even one day.


I know this is a commom problem with 1st gen b16's and I need responses from whoever has experience with this particular problem. What was the solution that worked for you?

Any help or feedback is appreciated.


Modified by SiRWanabe at 2:07 PM 10/27/2003


Modified by SiRWanabe at 3:09 PM 10/27/2003

 

O2 sensor #1 is:
C16 on the PR3 or PW0 ecu
GREEN connector
monitors cylinders 1 & 4

O2 sensor #2 is:
C8 on the PR3 or PW0 ecu
WHITE connector
monitors cylinders 2 & 3


If the o2 sensors are monitoring the wrong cylinders, you may be richening the cylinders that are running rich already and starving the cylinders that need the fuel. This is worst case scenario, but possible. I would make sure they are right.

 

I meant C8 and C16, my fault it was a typo.

I want to get feedback from people who have had this problem. TIA

 

ttt.

Just trying to get an idea of what I should try first. Now I know you are probably saying if he knows all the solutions why is he asking?


Because those are possible solutions, and I want to know the solutions from different people who have had this problem. If you have had experience and fixed the problem let me know so I can start from there.

 

option 6 look for a used zdyne one wire ecu on ebay they go for about 125 thats where i got mine.

 

Like I said, wire it right. It's not hard.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ricodemus &raquo;</TD></TR><TR><TD CLASS="quote">Like I said, wire it right. It's not hard.</TD></TR></TABLE>


I didn't the wiring, but the guy who did is really good. I'll figure it out, I was hoping to get some feedback. Thanks for the replies

 

read what camshaft had to say(2 pages):
https://honda-tech.com/zerothread?id=404493&page=1
https://honda-tech.com/zerothread?id=404493&page=2

 

O2 sensors, like everyone is saying. If you want to try a quick fix unplug them both. If it runs much better, then they need to be reversed or wired in correctly.

 

had the same problem along with 4 of my friends.. switch the pins at the ecu.. easiest

good luck

 

Same here, same symptoms as your car. Reversed the 02 sensors wiring at CPU, no more problems.
Good luck

 

Update:


I just unplugged the connectors for the o2 sensors and the problem is gone. They are connected on the header but the plugs are disconnected. The wiring was correct, as I thought so that wasn't the problem.


Will this cause any problems running without the o2 sensors connected?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SiRWanabe &raquo;</TD></TR><TR><TD CLASS="quote">Update:


I just unplugged the connectors for the o2 sensors and the problem is gone. They are connected on the header but the plugs are disconnected. The wiring was correct, as I thought so that wasn't the problem.


Will this cause any problems running without the o2 sensors connected?
</TD></TR></TABLE>

It wont cause any problems, but you will probably run rich since the ecu is running open loop since its not getting the feedback from the sensors. Either means the sensors were bad or they still need to be switched.

 

Why mask one problem with another? Switch the pins at the ecu and you'll be done.

 

As stated, it will run rich all the time. No other side effects except it will throw a code when you're coasting in gear for &gt;10 seconds or so. I actually drove like that for quite a while before we all figured out the 'switch the O2 sensors' trick

Just switch the pins at the ECU and reconnect the sensors. Takes no more than 5 mins.

 

Why would I switch the pins at the ECU if I know they are correct? I appreciate you guys helping me out, I just don't understand why I would need switch the pins at the ECU if I know they are correct.


I bought new o2 sensors and they are getting put in friday. I hope this will solve the problem, but should I switch the pins at the ECU anyway while the new o2 sensors are getting put in?

 

If it's bogging and hesitation with the O2 sensors connected, and unplugging the sensors (temporarily) fixes the problem, chances are they're reversed. The logic is as follows: With the O2 sensors connected, the computer sees the primary cylinders running rich (though it's actually seeing the secondary cylinders). The computer leans out cylinders on a pair-by-pair basis, starting with the primaries and then modifying the secondaries, so it leans out what it thinks are the primary cylinders. Unfortunately the computer is atually leaning out the secondaries (the ones it's not yet looking at) so it ignores that information and keeps leaning out the cylinders until the car bogs out and loses power, possibly detonating. When that occurs, the ECU freaks out, retards the timing, and dumps fuel, solving the problem and eliminating knock. When the ECU sees no more knock, it figures everything's peachy keen and begins leaning out the primary cylinders again. Rinse and repeat.

Switch the pins now, reconnect your O2 sensors, and see if that fixes it. You won't wreck anything unless you break a pin or the ECU harness. Then when you get new O2 sensors coming in, you can enjoy the benefits from those.

 

Thanks for the help, greatly appreciated!

 

Dude, stop hacking and solve the proble right.
Install the new O2 sensors you are getting.
PLUG them in.
Go for a test drive .
If the car still hesitates, then swap the wires at C8 and C16.
problem solved.

You are making things far more dificult that they really are.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The new Spaceballs &raquo;</TD></TR><TR><TD CLASS="quote">Dude, stop hacking and solve the proble right.
Install the new O2 sensors you are getting.
PLUG them in.
Go for a test drive .
If the car still hesitates, then swap the wires at C8 and C16.
problem solved.

You are making things far more dificult that they really are.</TD></TR></TABLE>


I am solving the problem right, I unplugged the sensors to verify that was the problem.

I am installing them friday if you didn't read that in my previous post.


And if the new sensors don't do the trick I will switch the pins in the ECU. I ask questions when I dont know ****, by no means am I making things more difficult, I was troubleshooting the problem the way I thought was the best way.

 

Troubleshoot before you get the new sensors Just switch the pins NOW.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">Troubleshoot before you get the new sensors Just switch the pins NOW. </TD></TR></TABLE>


Yeah I can always return the sensors if the pins do the trick. Thanks again

 

I have (probably) a stupid question. I've heard some people talk about if your o2 sensor(s) are plugged in that it will give you more power. Is this true?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TrickyRex &raquo;</TD></TR><TR><TD CLASS="quote">I have (probably) a stupid question. I've heard some people talk about if your o2 sensor(s) are plugged in that it will give you more power. Is this true?</TD></TR></TABLE>


No it doesn't matter, at WOT the ECU is in a set ignition/fuel map and it won't matter.

o2 sensors matter under partial throttle and emissions.

 

So will I get better gas milage with them plugged in?