Pinging W/tune And 91
 

After a recent smog, I reinstalled the diablo tune back into my 01' f150 screw 4x4 w/5.4L. I have used 91 Shell for as long as I've had the pred. I decided to go out in the country and floor it, just to see if it was as good a I remembered. I noticed that there was pinging at wot just before each upshift. I had never noticed that before, But I probably had the stereo on and could never hear it. Diablo recommends a 10% retard, it was done, and still pings. (although not as hard) If I go another 5%, then I will be at their settings for 87 octane. Diablo told me that I could have an ignition problem of fuel filter issue. This is not the case! I am not a tuner, nor do I have access to a dyno. I do not want to piddle with air/fuel changes over and over. Any suggestions before I sell it to somebody else and get a custom tune from Troyer?????

Sounds to me like you either have to increase the octane level or retard the timing enough to stop the spark knock.

How old are your plugs?
Have you cleaned your EGR ports?

These two things (plus replacing a faulty DPFE) got rid of a ping that I had.

Plugs have 70K and egr ports are clear. What do you think about retarding the timing 10% and lowering the a/f ratio (richer) in the 4-7K range by a point or two? It make sense since all these canned tunes do is up spark advance and lean out...Your thoughts?