2004 Cadillac Seville SLS Q&A

2004 Cadillac Seville SLS Question: I went through Echeck & failed the following codes came up

po171-po174-po300-po410-po741 & check engine light does not work.I bought another PCM. -
Answer 1
you have lean codes of 171 and 174 both banks misfire codes po300,emisssion issues with air injection po410 and trans codes po741 -
Comment 1
How do trouble shoot the problems -
Comment 2
this may be beyond your capabilities,sorry not trying to be harsh. i rec you seek the help of your mech to diag every issue.alot of people get some info and just start replacing parts that are not needed,so to prevent wasting $ get proper diag -