I've been having problems getting my car mapped - 1 year on the road and it's still not right
Yesterday I changed the fuel pump (low/inconsistent pressure - seems to be sorted now) and went for a drive armed with the trusty laptop , intending to do some logging .
Using megalog made it so weak it was undriveable .

But while it was spitting back and popping constantly from the exhausts , the AFR reading was showing around 14 - I checked with my gas tester at tickover , the CO was 0.3......

I then went back to `old skool` mapping - just adjusting the fueling till it sounded/felt right , and the AFR finished up at around 12 - any leaner and it was back to spitting/popping

The LC1 is all set to the instructions , and all the settings in megatune are correct AFAIK - what the fudge is going on

Is it popping back on overun or all the time.

All the time - when it does , the AFR goes fully lean , and it wont even pull away .
Having it richer cures this , but it still pops when coming off closed throttle ?

I think the LC1 is telling porkies - there nothing left to check / change .

I took my car for rolling road for the exact same reason. It was more of an explosion thow,watched it be done only to find out thay it was not far out through the rev range. But at the end of the sesion he sorted the popping on overun out by richening the bottom line up (40KPA) till it stopped, this was the opposite to what i was doing but it worked, hope this helps.

It dosnt pop on the overun - only when coming back on to the throttle ?

The LC-1 needs to be calibrated in free air, not only when you first set it up but the instructions say at regular intervals.
It may be worth doing it again.

i had this problem when i fitted my adjustable fuel pressure regulator, as the fuel pressure went from 66psi down to 44 the entire fuel table became far too lean, have you tried putting the whole fuel table up bu 10-15% and trying a run, that helped for me and eventually upt the table by about 20 odd %,

i would recalibrate the lc-1 and do a free air calbration. is it possible that the fuel table is correct but the acc'n enrichments are too low and its not putting enought fuel in when you press the accelerator?

have you selected lc-1 0-5v in the MS code calibration section?

just a couple of idea's

I changed the fuel pump yesterday , and sorted the low fuel pressure - it was only 30 PSI before , the new pump banged that straight up to over a hundred
It's now set at 45 , and yeasterdays run was to re-map with the proper pressure - initially it was rich everywhere , hence the attempt at using megalog .

I will pull the sensor later and do a free-air calibration - too busy machining throttle bodies at the mo

Yup. Sounds like a good opportunity to do a free air calibration to me!!!!