Hello All,

Have a 1994 Honda Civic VX, brand new rebuilt motor, almost all the sensors are new - ECU, IACV, etc. Runs 95% great, has power but it is chugging gas. Last 3 fillups were about 28-30 mpg on a car that got 45-50 mpg. The only code it is throwing is the 02 sensor (#1). The sensor was relatively new, about 2 years old. I replaced with a new one (5 wire, expensive!) and the ECU light is still on. I did reset the ECU, properly but it still has the code. Here are some of the things I noticed - plugs do have some black carbon around the thread base but the tip and electrodes are gray-white. The tail pipe has a huge amount of black build-up out the back forming spots on the driveway but no black smoke. Idle is fine, power is fine, vtec kicks in, however it does feel like it is loading up and the exhaust note sounds a bit different. I thought about the MAP or fuel pressure regulator to check but have not run through the diagnostics yet. I think the problem is fuel related only as I did switch out the O2 sensors and even had a spare ECU, exact match, it still threw the code. Appreciate any help!

 

.....bump....

any body?

 

no one can help?