vp calais back firing

[brooke2012]

hi all i have a vp calais that is duel fuel
last cple of days it's been backfiring leads and plugs have been changed 6 months ago
the car seems 2 be fine when i start it up until it gets warm about a quarter of a tank then it starts backfiring it has blown my pod off the air intake. can somebody help plz how 2 fix this problem.. thanks any suggestions will help

[vn_v6]

thats front firing mate. backfire is out the exhaust

[mr calais 5.0]

My motor mechanic says its a common prob with v6's on duel fuel..

[brooke2012]

yes someone said it could be the mixer how do i check the mixer