help! weird problem???

i am an old 5.0 guy. i have owned about 8 or 9 of these. okay, here it is. my 03 gt already had flowmasters and jba shorty headers with the stock h pipe. i added a mac with mil eliminators off road and now i am having a pinging prob in first and second gear. when in higher gears at wot the prob is not there....it really happens under wot in lower rpms in first gear and transfers into the sencond gear shift then it is gone ??? maybe it is real lean in the first two gears? i am running 93 octane with no timing adjuster. i just decided to reset the computer after adding the h pipe??????????????? :shrug:
 
troyGT03 said:
i am an old 5.0 guy. i have owned about 8 or 9 of these. okay, here it is. my 03 gt already had flowmasters and jba shorty headers with the stock h pipe. i added a mac with mil eliminators off road and now i am having a pinging prob in first and second gear. when in higher gears at wot the prob is not there....it really happens under wot in lower rpms in first gear and transfers into the sencond gear shift then it is gone ??? maybe it is real lean in the first two gears? i am running 93 octane with no timing adjuster. i just decided to reset the computer after adding the h pipe??????????????? :shrug:

assuming that your car was used maybe that's why the original owner wanted to sell it. Ask him if he had any other performance mods and explain to him about the problem. If he denies say fu