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OK, my car has been running perfect for over 2 months with the Ktuner ECU using a 2003 accord harness in a swap vehicle, one day it started to run really rich on idle and even died a few times. Sounded like my cylinders are flooded with fuel and It had a really strong smell of fuel. The car eventually started after I took off the spark plugs. Intermittent hesitation at low RPM followed next during normal driving.

To make the long story short I decided to test the fuel injectors and found out the #1 injector was stuck open. I replaced it with a known good running RDX injectors and it did the same thing. After hours of trouble shooting with wiring with no obvious wiring issue, I decided to plug in my Hondata KPRO (modified for 2005-2006) with the appropriate conversion harness from Hondata as well and everything fired right up no issues!

The weird thing is the car will continue to run with the Hondata even with the ignition key turned off!!!

I then took off the Hondata and re installed the KTUNER and the misfire and hesitation is back.

My questions are these:
1. Why would the car keep running with key off using Hondata KPRO and it would not do it with Ktuner?
2. Is the hesitation and misfire a sign that the KTUNER ecu is bad since Hondata KPRO does not have the same issues?
3. Is there any test I can conduct to test if the Ktuner or Honda mother board is damaged?

Thanks

Interesting issue.

Could be ECU or wiring.
The ECU controls the injectors, not the KTuner board. The KTuner board wouldn't be the cause. The ECU may be.

OK I think I know the reason why the car will keep running while ignition key is off because I can still see the green LED illuminating from the Kpro ECU even with the car off. That means that it is still getting power somewhere even when ignition is off.

I took the car for a drive around the block and I'm now still experiencing the same miss fire and overly rich AFR as I did on KTUNER, I think for now I will say that it might be a wiring issue making the number 1 injector to be full open. Any suggestions on why the injector is doing this just on number 1 injector???

KTuner wrote:Could be ECU or wiring.

I already made these suggestions.

You can see in logging the expected pulse time for all injectors to tell whether it's something tune related.

I dont think its tune related because no change was made and been running the same tuned map for almost 2 months and this just happened recently. I will datalog it and look at any anomaly

It probably isn't, but I always suggest looking at the data you have available.