Hello all,

My mothers E320 has a CEL again. Last time it was thought to be a throttle body and we replaced it (the wiring was deteriorated).

It has since come back on twice, but only while the car is decently warm. Both times it has come on has been while it was sitting at idle for 10-15 minutes. I checked the codes and it blinks 5 times which points to an EGR issue.

Anyone have any ideas on where to start? 02 sensor maybe?