Ex running lean

[david34]

I have a 1994 civic that's failing NOx and I checked the spark plugs and they are white I was thinking it could be the fuel filter I have new plugs wires and distributor cap what else should j check i t also has no engine codes

 

[mc360]

I'm not of much help but did you get the cat hot before taking the test? You want to get the cat hot and not let the car sit more than 10 minutes before it gets tested. Maybe try some seafoam through the gas tank and intake system to clean the injectors and intake/exhaust valves and piston tops. If you need to I have heard a bottle of 90% rubbing alcohol dumped in a half tank of gas will help clean stuff also and help you pass