I have a civic EK9 (1999) and i have an obd1 ecu with Jun chip. So i bought a conversion harness (Xenoctron Tuning) which fits perfectly but vtec doesn't works and "Check Engine" lamp is on . This is problem from Conversion Harness or from my car's harness?.
I say the cheap ass eBay chip. I would highly doubt the conversion harness is failing but then again there can be the odd bad ones.