I've got an '06 that has back-fired ever since I gutted my cats. I put on the Dan Kyle block-off plates (which didn't have any sort of remedy), and I just got it custom mapped (which helped quite a bit). But I still get a single infrequent 'POP' at around 3000 rpm under decel with the throttle completely closed. Is this an indication that it is running lean??? And would changing the map (either more or less fuel) at 0% throttle remedy this at all????