I HAVE A 98 EX CIVIC. THE ENG HAS STOCK INTERNALS. INTAKE /HEADERS/ 2.5 INCH PIPNG FROM THE HEADER TO THE MUFF WITH NO CONVERTER. I AM HAVING A PROBLEM WITH MY CAR RUNNING RICH. I NOT SURE IF ITS A 02 SENSOR OR ECU PROBLEM OR IF ITS A STUCK INJECTOR OR VALVE. JUST WANDERING IF ANYONE ELSE HAS HAD THIS PROBLEM OR KNOW WHERE TO START.
Is there any check engine light? If there is a check engine light that would be the place to start. I would check the fuel injectors just to make sure they are opening and closing. I think you can listen to the injectors to hear them opening and closing. You could also get this trigger thing that you point at the injector and it flashes a light whenever the injector opens.
I DO HAVE A MIL FOR CODE PO420 WICH IS CATALYST DETERATION. BUT ALSO KEEP IN MIND THAT I HAVE NO CATYLITIC CONVERTER ,HEADER AND 2.5 INCH PIPING BACK. I ALSO DID RESEARCH ON ALLDATA AND THEY SAID LOOSE TERMINALS ON THE DISTRBUTOR WILL ALSO CAUSE THIS CODE TO BE PRESENT IN THE ECU.
yes i do have (2) o2 sensors. i know im running rich because there is a 1/4 inch of carbon on my bumper and i get about 250 miles per tank. im just wandering if this is a common problem with hondas or just mine
If you dont have a cat the ECU will think somthing is wrong because your 2nd O2 is gonna be the same reading as the first one. You need to get a 2nd 02 sensor device that fools the ECU into thinking that you still have a cat.
I don't think that a P0420 will cause your engine to run rich. That code pretty much just says your cat is bad/not doing anything. What is the voltage on the 1st O2 sensor? If the sensor is varies between 100mv to 600mv, then there isn't a problem. However, if the sensor is showing that there is always a lean mixture then that is a problem since the computer will try to richen the mixture by adding more fuel. If you can find a way to make the 2nd O2 sensor give a reading off 100mv then the code will go away, but since the O2 sensor isn't a passive sensor i don't think you can just throw a resistor across the terminals of the sensor.
Y8 RUNNING RICH
