Hi Im new to this forum and recently picked up a 1997 Civic EX with a B18B1 Swapped into the car. Heres some background Info. Ive noticed at best I can get is 25mpg out of the car. Very moderate driving and Little to no AC use. The car lacks power steering but does have 17" wheels weighing in at 38lbs with tires, full bolt ons and supposedly chipped ECU (NO Proof but does have 2 step).
I was doing basic tune up maintenance and Noticed no Primary O2 Sensor or wiring at all. I got under the car to find the 2ndary O2 Sensor installed but cut and not going into the harness from the car body. The Wiring looks well done but I cannot find any primary O2 Sensor plug or spot in the header for it. The car is Running and Xact Dyno harness OBD2A-1 and a OBD1 92-95 ECU. I think the CEL does work as I have turned Key halfway and it appears but I have no CELS at all for O2s. Because of the swap would a CEL not appear and will I never get CELs because the car is a OBD2 using OBD1 ecu? Or could it have been Truly tuned out? If So will a tuned out O2 kill your gas mileage? Also off topic but I have a P75 Head which should mean I have a 96+ B18B1 shouldn't it use an OBD2 ECU? Im a newbie to Honda so Any information is appreciated.