i have a 99 f150, 4.6L, auto..it has thrown two codes at me..P0172 & P0175..it says that banks 1&2 are too rich..i put an air intake system on a couple of weeks ago and 80 miles later it threw a code and said that bank 1 was rich..the guy at advance auto said the o2 sensor may be dirty and to clean it and reset the comp..i did that and everything was fine..the o2 sensor was not too dirty.. now a couple of weeks have went by and it has thrown these two codes saying that both banks are rich...it also idles a little rough as well...it idled rough before adding the air intake to it...the iac valve seems to be working properly according the the snap-on scantool scanner...pcv valve seems to be working properly as well and the vaccum lines seem to be in good shape as well...does the comp need to be reprogrammed for the new intake system?? and what could be causing the rough idling..if anybody has any ideas, lets hear them..thanks..

 

if your cold air kit uses a filter that is oiled, then remove the mass air meter a VERY gently clean the meters sensing wires inside of the housing. its possible that oil could have contaminated the sense wires and cause some faulty readings from your mass air meter.

 

Use a electronic cleaner auto parts store have it do not touch those wires.