No matter what it has to be scanned, especially when the problem happens,.
could be a coolant temp sensor sataying in the cold mode, this will not set
a code, this is the starting point only.
> My 01 Impala 3.8L takes more than 5 minutes in the morning for the idle to
> go down and when in drive it shakes and makes more noise than usual.
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> I am assuming if the engine light is "on" a fault will be stored.
> Thank you for any suggestions.