Car starts but only runs about 5 seconds - 1999 Dodge Intrepid

Is this a Ferrari or a Kia?
Year, make, model and engine size

sounds to be the ign.module is failing after car warms up

alarm/immobiliser needs resetting.

catalitic converter is clogged up its not lettig the car breath

Turn on the key and listen for the pump to run for 5 seconds. If it does, repeat this process about 5 times.
spray starting fluid in air intake too.

THEFT DETERRENT MODULE OR MAYBE KEY NOT BEING RECOGNIZED BY MODULE. CAN BE REPROGRAMMED. DEALER MAY TELL YOU HOW.

ok here you go
make sure the battery is fully charged befor starting
turn ignition to run
attempt to start once then release the key in the run position
let vehicle sit with the key on for ten minutes
the security light should turn off
turn igniton switch off
wait 5 seconds
turn key to run position
let vehicle sit for 10 minutes
turn key off
wait 5 seconds
turn key to run position
let vehicle sit for ten minutes
turn key off
wait more than 6 seconds
and start engine

Disconnected what line?

sounds like you have a bad ECU unit. have it checked.