backfire normal?

[90blackdsmturbo]

I have a 90 laser turbo fwd and i just have intake,hacked maf star gone and lower honey comb, 3" catback, empty cat, boosting 15 spikes at 17 though and when i recently put on my intake pipe it backfires after i let off. Is this normal? it did not do it before on the original stock rubber intake pipe. I was thinking about changing the gap on the spark plugs maybe this would go away? What do you guys think maybe im running more lean since its drawing a little bit more air into the motor? your inputs are welcomed

 

[dustyb]

my friends car used to do this, but it was because he was runnin quite rich. i guess the unburnt fuel hit the hot exaust and backfired.

 

[90blackdsmturbo]

it backfires and then it smokes white smoke a little bit for like 5 seconds or so and then it goes away im pretty sure im not running rich because im on stock fuel pump and stock 450 injectors with no pressure regulator