Hello all,
First off, I have a K20a type R swapped into my 05 civic. The problem I have is that when I installed my wire conversion harness, the wires did not match the wires for the 02 sensor so i cut the connector and spliced them myself.. Worked great, no codes.. I street tuned my car and it seemed to run well, except I have some mild knocking during high load at low RPMs (2500 to 3000) that I cant seem to get rid of.. Well I recently went to a dyno day that our car club went to, and according to their dyno AF sensor, I am off by one point all across the board. My KPro tells me im dead on at 14.7, and the dyno says 15.7! So could the way it is connected have to do with this, or is my sensor just worn out? How do I test this? Thanks for your time!

 

No real way of testing except find a friend and borrow his. Or take yours out and see how dirty it is. You can try cleaning it with a wire brush and some carb cleaner.

What did you instal this into?

 

Thanks for the reply! I will try out what you said and see if it makes a difference... The motor was put into my 2005 EM2 civic

 

from your avatar I thought so, but just making sure. I was wondering why you had to splice an 02 sensor harness lol


Obviously its getting a signal so it must be wired somewhat correctly lol Only four wires:

Signal Wire
Signal Ground
Heater Power
Heater Ground

If you screwed it up you'd have a CEL for heater circuit and problem 02 air fuel code

 

I am just concerned about added resistance in the spliced connection vs. a proper clip, possibly throwing off voltage levels

 

Yeah, that is one thing to be cautious of. The O2 reads off of voltage levels and if anywhere in your splice job you created a higher or lower resistance than it is used to reading you could have thrown it off. You might be able to find out what voltage or resistance they should be running somewhere and then use a multimeter to find out what yours is running.

I wish my NTK Oxygen sensor rep was here... He would probably know this. Let me know if you can't figure it out and I will give him a call for some insight.

 

ttt

 

Aren't ep/rsx primary o2 sensors wideband? I always assumed so because Autozone wants like $300 for it and $70 for the secondary.

 

A/f sensors are a lot more then regular ho2s. They are also a lot more accurate and faster the a regular ho2s

 

Yes they are wideband, and expensive.. I would hate to pay for a new sensor and realize the old one was fine and it was the wiring causing the issues.

Does anyone know where to find out what the proper voltage / resistance levels are for the 02 sensors for these motors?

@Square_1: If it's no trouble to find this out, that would be awesome! Thanks for the help!