For the past week whenever I try to start my car it runs for about 5 sec and dies. After about 5-6 tries it finally continues to run. Once anda while it will start fully and the immobilizer indicator will flash on the dash and the emergency lights will turn on (and I can't turn them off) Some posts say its an immobilizer ring in the ignition otherssay its the ecu. Any way to find out for sure?And if sowould it be a DIY fix?

2003 A4 Quattro1.8T Manaul Trans.

Anyhelp would be great