Hello,

I have recently completed chipping a p06 ecu to run my 5th gen. I was doing some reading about low and high impedance fuel injectors. I was wondering when I plug in my ecu is it not going to be bothered by the high impedance fuel injectors in my car because of the civic being older and having low impedance injectors?

 

Or does it not have low impedance injectors in civics 92 and up? I've seen it listed both ways online and I don't know what to believe. I guess I will head out to the junkyard with my volt meter to measure resistance on injectors if all else fails.

 

OBD1 ECUs require high impedance (saturated) injectors (10-12 ohms). If you run low impedance (peak & hold) injectors (4-6 ohms), you need to use a resistor box which adds impedance inline with the injectors to increase it.

If you run low impedance injectors without increasing the resistance, the ECU will function, but the injector output transistors will eventually short requiring repair.

I see and repair this issue all the time for customers unaware of the incompatibility

 

Thanks for the response, so if all obd1 and obd2 ecu run high impedance injectors then I shouldn't have trouble when I do the switch

 

Ok so let me put it like this. Im putting a chipped p06 ecu in my obd2 prelude, I have the conversion harness to make everything plug up. Is my car going to run right with the stock obd2 high impedance injectors, the obd2 distributor, and everything else or are there other modifications that must be done to make this ecu run my car or is it just plug and play. I do know that the iab plates are wired different (obd1 being constant hot required with ground from ecu, obd2 constant ground, 12v from ecu)

 

Here is some more reading on it if your interested.

http://www.enginebasics.com/Engine%2...ctors%202.html

 

Your saturated injectors will work just fine. Don't forget to add the VTEC and IAB components to the appropriate circuits inside your P06 as well. If it is a USDM ECU it will be a ground @ ECU for the IAB activation. Unless you can change it in the tuning software.