Evening all,

This maybe a chavvy question but im interested in the theory behind it, sooo I happened to come across a car meet a few weeks back where a mk6 fiesta (zs maybe) was backfiring shotgun shots even when not particularly revving it.

I know an excess of unburned fuel causes a backfire and the car in question had cheap mods so I can only assume he wasn't using after market management (omex etc).

So my question is how how would you suspect he'd done it? Can you buy chips to allow a little more fuel, advance the timing using adjustable pulley's, bigger injectors, or something else? Are there any repercussions from running more fuel other than killing the cat?

Thanks