E30 Zone

dont know what to do help !!!!!!!!!!!!!!
the engine is backfiring badly its idling really bad and i can hear a noise coming from around the inlet manifold any body any ideas please .

Noise around the inlet manifold as in hissing air? If so you've answered your own question.

would an air leak cause it to be undrivable
also i ve just been looking on zone could it be my icv it says on one that i should be able to hear it buzz when you first turn key in. ive got nothing. i also unplugged it whith the engine on and it made no difference.