Hondata

Before I get the "you should have bought a PLX not a UEGO" in my defence I didnt find these forums until now :roll: .

I have a H22A7 motor which was tuned for me (not by me). I have the map from the tuner so I know I'm working with what has been tuned. It has some basic bolt ons, not boosted (yet...).

I got an AEM UEGO and followed the vast amount of posts here. The aim just to log the AFR readings, not thinking of running closed loop yet. I followed the instructions and cut D10 but starting the car it runs really rough and the AFR fluctuates wildly between too lean and too rich.

The map is running in open loop. I tried setting the Wideband to D10 ELD in the closed loop and uploading the map but still the same.

Apologies if I've missed something and this is a bit noob... Why is the car now running so rough?

the way i understood it is that the stock o2 sensor is used for closed loop (unless you use a 1v analog wb output to the stock o2 sensor input).
the 5v wide band input is used for autotune and datalogging.

Apologies, vital piece of info missing...

I've installed the AEM UEGO into the rear o2 sensor position, stock o2 is still present.

You should not put a Wideband after the cat as it will not be accurate.

I have no CAT, just a test pipe.

I think I found the problem. When I was identifying the D10 wire on my conversion harness the wires for B20 and C31 came off! :roll: I took off the harness and a closer examination revealed really bad soldering :evil: .

Harness resoldered and went for a test run. Looking at the gauge only, low speed cruising and idle Air/Fuel ratio is in the high 15s/16s is this right :?: . High speed (in VTEC) is spot on 14.1 (ish)...

Still running in the upper 15s I have patched D10 back. The motor is now running fine. Still in OPEN LOOP.

I'm confused, all I wanted to do is log the AFR why did cutting D10 result in the car running rough? Sorry if this is obvious question but I feel it needs to be answered.

Figuring possibly because I hadnt adjusted any voltage offsets for the WB, I followed some posts here and made some adjustments but the gauge still read high.

Final question, does the ECU adjust fuel based on the WB reading on D10? I thought this would ONLY happen in CLOSED LOOP?

Most likely you have something wired incorrectly if just inputting a wideband signal to the ecu causes the engine to run differently. Check to make sure you have input it into the correct pin.

far2wired wrote:Still running in the upper 15s I have patched D10 back. The motor is now running fine. Still in OPEN LOOP.

I'm confused, all I wanted to do is log the AFR why did cutting D10 result in the car running rough? Sorry if this is obvious question but I feel it needs to be answered.

Figuring possibly because I hadnt adjusted any voltage offsets for the WB, I followed some posts here and made some adjustments but the gauge still read high.

Final question, does the ECU adjust fuel based on the WB reading on D10? I thought this would ONLY happen in CLOSED LOOP?

1.Frequent downloading the maps off the ECU causes corruption, reusing the maps won't reveal anything, but when you load it, the car runs rough. I encountered this issue when reusing downloaded maps multiple times.

Status: Solved. Made a new base, and tuned again from there, this time actually keeping a copy on the laptop.

2. Trust the wideband readout more than the D10 input you wired the wideband to. Sometimes voltage offsets (mine was intermittent) occurs due to bad grounding or interference, and the readout on the hondata is a little off, or a lot, depending on how much voltage offset there is.

Status: Solved grounding problem, drove a few times, adjusted the voltage offset so the hondata output the same numbers off the wideband.

3. The fuel adjustments are based on the option 'disable closed loop' but if you reloaded the maps of the ECU, there's possibility of it being corrupted slightly. Which is why there's a warning from "downloading off the ECU".

Status: see 1.

Hope that helps.