I have a 2000 civic si with stock computer, it is running really rich and the problem started recently. i cahnged plugs, wires, fuel press regulator, 02 sensor and the car is still running extremely rich around 15mpg highway. Can anyone help me figure this problem out, i have no idea what to do now ? It also misfires intermittently when driving if holding the gas pedal constant but it will clear up if you floor it. It's throwing codes for 02 sensor bank 1 voltage high, and also fuel system too rich. help !!!!!!!!

 

Map sensor?

 

if you smell gas at a stop, oil smell like gas and have bad mpg then fuel pump.

 

^ +1

 

What is the the specific O2 sensor code? You obviously need to check the primary O2 sensor wires and possibly replace the O2 sensor.

And why didn't you also replace the cap and rotor along with the plugs and wires? Have you checked the ignition timing with a timing gun?

 

FIXED : I did a valve adjustment and changed the 02 sensor again. the first one got killed by the car running rich for 2 yrs due to out of spec valves. CEL is now gone and getting 30 mpg again. Thanks for all your comments guys !!