I swap my 98 civic EJ6 with a D16Y8 engine. I use an OBD 1 ecu with conversion harness. Because the engine didn't have a VTEC oil pressure switch (i found that JDM engines don't have it ) i programmed the ecu to work with a D16Y7 program (header, 240cc injectors). I had no problems, no CEL Codes. The engine is working perfect.

Yesterday, a friend gave me his VTEC pres. switch (B16) to test my engine. I burned a stock D16Z6 program.... and here is the mystery, CEL CODE #19 (the car is M/T) when i'm changing back to Y7 chip.... NO CEL. Is this possible????