after installing my 87 octane tune on my car that has been revised 4-5 times already.as trying to fix the problem. My issue is when I drive my car it is fine from moderate to heavy take off ,but I have noticed when I cruising at low speed (roughly 10-20 miles per hour) in idle mode and when tap the gas real fast I hear a ping/clanking sound that lasted about a second then clears out. It only does this when loading a tune, not in stock and Right now I have 93 octane in my car now . Clean throttle body . changed air filter and new spark plugs . Car is Fully stocked 2004 GT Mustang ,
They want me to data log which having problems following the instructions ,,,any thoughts??

 

Silly question but are you running premium gas and premium gas only in your GT? Maybe try a little octane booster every few fill-ups. Or they may have to remove some timing from the tune.

 

Not trying to give ya a hard time, but why run an 87 tune in the first place?? It came stock with one.

Since you have premium fuel in it, run the 93 tune and call it good. Of course nobody wants their fuel mileage to drop from 20 to 14, but if you're running the 87 tune because it promises "increased fuel economy" or whatever then you're probably in the wrong car for that. Besides, the difference in mpg between any 87 and 93 tune would be minimal and dependent more on your drivimg habits anyway.

 

Disagree on that...lol I had a 91 tube and a milage 87 tune. Huge difference in mpg, and I don't mean 20 to 14. I averaged 18 on my commute with 91 but that's daily, when I went on a long road trip all highway I uploaded the gas tune, because it pretty much ran like crap so only long cruises. Got 30.8 mpg over 200 miles as far as ops problem, sounds like too much timing down low, which is a weird issue to have on that kind of a tune.

 

Is it a mail order tune?