I hope I'm posting in the right spot, if not I appologize. I ordered the SCT tuner from mustangtuning last Christmas. I realize that with the 91 octane tune it came with the car has been pinging in 4th and 5th w/ or w/o ac on under heavy load. I went through the standard pinging solving methods (cleaning MAF, octane booster, fuel filter, seafoam, etc...). I switched to the stock tune and now my car runs fine (except for the check engine light bc of headers, and the speedometer is way off). I need to find out what I should do to get this fixed and once again I hope I'm in the right place

Gabe

I had LT headers w/ catted hpipe added since the tuner but I don't think that would cause pinging? I always use 93 octane

 

You need to get a new tune. BTW, running 93 octane on a stock tune is a waste of money, so while on stock tune, run 87.

 

Yeah that pretty much sums it up.

 

Have you tried changing the timing settings w/ the tuner? If not, try retarding the timing.