i had this problem with my last truck. 87 octane it would have the clattering noise under low rpm pulls and still some at higher revs. was told it was a timing issue. that truck was an explorer sport trac and there was no tuner available for that one. mine now before i got my edge evo ht did the same thing. it would go away if i used 89 or 93 octane but still was noticable. i run the 93 tune on my edge and of course the proper octane. from my searching on here i saw i should retard my timing and see if that helps. but how much is too much? the most ive gone is -2 (im assuming thats 2 degrees) it will go a total of 4 either way. im a novice when it comes to timing an engine. so i was seeking some advice in how to do this the right way. current mods are just a K&N drop in filter and a flowmaster cat-back. on the extreme tune currently it is not bad but i can still notice it sometimes. if i put it on the 87 tune and run 87 octane it is very noticeable. sorry if this is bringing up an old topic but i did search and still have a couple questions.
thanks