I took my car in for EPA test....everything else is good except it is burning too rich during the idling...
I replaced the 02 sensor and spark plugs and didn't make any different.
How can i lean out the fuel burning when the car idling?

PS NO ecu code ..so must be okay
plus I have the big cold air filter..

 

Have you done anything to the exhaust system or catalytic converter?

 

just added the header and kept the stock muffler set up
I passed EPA test before bearly and I having drove the car for two years...

 

Well, you might want to be specific on what is all done to your exhaust, and what kind of car it is.

 

The car is 95 del sol
it got the stock exhaust except the header...swap[ed JDM B16 motor and tranny...
Upgrade Air filter...
The car running completed JDM drivetrain.

Can I adjust the fuel pressure or mixed air and fuel setting?

 

You should also try posting here they might help you more...

https://honda-tech.com/zeroforum/1