my truck did not pass the smog test because of emissions on 1997 Ford F-150

i try to read the codes but there was no codes for emissions what could be the problem truck is 1997 v6 ford f.150 pick up

by in Indio, CA on October 02, 2012
1 answer
ANSWER by , October 03, 2012
need eng codes or exh readings from test, post so we can adv