Hi.

Level 1 is a trans-only tune on an EVO. ( this IS an EVO Model # 15051 is it not, or is it a CS/CTS? ). So yer running a stock calibration, in effect.

Cheap gas is usually .... well, Cheap Try Chevron, Texaco, Shell. And if you can find ethanol-free, even better. See if a tank or two running that helps. Could be that simple.

As I say, tuning is more demanding of several things - fuel quality being right up there near the top of that list. Throw a bottle of Techron in the tank too ( use nothing else). It's an excellent fuel system cleaner. Wallymart sells it - get a bunch if you find it on sale anywhere. One bottle @ oil change time (in the gas, lol).

Good luck.

And - yer welcome.

Cheers
MGD

 

Also check your vacuum lines for leaks (they deteriorate), and anywhere else that is sucking air not read by the MAF. When I replaced my intake manifold gaskets, I could see traces of leak-by on several ports.
One other thing that may sound like pinging is intermittent and slight engagement of the IWE system under low vacuum conditions. I've been down that road before. Bad vacuum check valves can cause that.
I run my Edge of level 2 with +1 timing and 87 octane, NO pinging at all. As stated, you need a clean and properly tuned up engine. On your Edge display, use the ignition timing as one of your 'gauge' options. Then when you are hearing the ping, see if the PCM is dropping timing to compensate. You may need new knock sensors. This is a good time to replace those manifold gaskets as well, and clean the IRMC butterflies, as you need to remove the intake to get to the sensors anyway. BTW my truck is an '05 with 115K miles on the clock.

 

Well looks like I got a lot of investigating and work to do....