Failed emissions test
 

I just took my v6 to emissions and I failed. The print out they gave me reported a diagnostic trouble code: P0171 And I checked my manual on that code and it said: "System too lean (Bank1)". I had just recently installed a MAC cold air intake, is that affecting the car; if so, how can it be fixed/adjusted?

Also, on mil status it reported "mil command on: fail" what does this mean?

And last how do i run a test to find out why my check engine light is activated?

Thanks

any mods to the exhaust?

what other things have you done to it performance wise???

It's mainly stock '96 v6 single exhaust. The only changes are new Bosch Platinum 4 spark plugs and MAC cold air intake

i aint no pro about all this or anything but i know that ford puts catalytic converters on the cars to control the emissions now if that has gone bad u might have to replace it or if u bought it used the other guy could have changed the exhaust and they messed with the catalyctic converter that could cause u to fail your emissions but this is just my opinion i dunno for sure though