I recently installed a remanded engine in my 2001 crown victoria. It has stock PI intake, accell coils, throttle body spacer and cold air intake, magna flow converters (rear cats deleted) and flow master mufflers. When I drive the car no problem at all. But siting and ideling I get a bank 1 bank 2 too lean codes. And u can smell gas in the exhaust. I couldn't find any vacuum leaks at all. Not sure what all could be the issue at this point. The CEL light comes on during this. But after overnight it's usually off and comes back on when I've been ideling for some time.
My car has 10000 miles.
My car has an automatic transmission.
Since you are using a cold air intake and most likely an air filter that is oil sprayed on it. These air filters are known to pass some of the oil that is put on it and will contaminate the mass air flow sensor causing the lean condition. The reason is the mass air flow sensor cannot measure all the air going into the engine. You can try to clean the mass air flow sensor and the intake throttle body of any excess oil. Make sure to clear all codes and the computer should be reset to start fuel control from new.