Punisher121

Would I know if I'll already put some wear on and or damage to the pistons and valves? Any signs of this occuring?

clowe1965

It would have tripped a CEL if it had. Short of tearing apart your engine you need to rely on your computer. The damage that would occur from this mod would be knocking, and there are sensors set up to detect this. The only other side effect that running slightly lean would cause is excessive heat to the spark plugs. This will shorten their life span but not so much that you need to replace them immediately, as long as you do not continue to run lean. Take one out and compare it to some pictures of plugs ( http://media.photobucket.com/image/s...kPlugChart.jpg ). If it is matches the overheating picture or is white then yes, you are running lean and need to fix it.

Punisher121

Thanks, that is very helpful. Here and at another forum I've been getting the range of responses as "get it fixed NOW" to "it seems ok without the CEL or knocking"....I feel like I'm ok right now, just no WOT until it gets cleared up. I'm either getting the stock airbox back on or a tune for the Steeda by the end of the week...

Punisher121

Just an update if anyone is interested, not in a much clearer position...The dealership I got the car from thinks the tune is NOT stock, although I wouldn't call their belief of the tune's status to be "scientific". Basically they said that since their laptop computer wanted to reset my car to "default" that this indicated it wasn't stock, but only way they could be 100% what tune was there was to retune it to stock which obviously I didnt have them do. My mechanic (kind of old school) ran a scanner, but states his Snap On scanner was updated last week and only has as recent as 2010 Mustang so he couldnt check the calibration codes to see if they matched a stock 2011 5.0 program...Scanner didnt show any obvious signs of running lean...I called Steeda directly and a local performance Mustang shop. Both said that if I floor the car and don't get a check engine or knocking, then they car should have the appropriate tune. I'm leaving the way it is at this point, mostly due to Steeda and the Mustang shop being positive I would have by now seen a check engine light or noise/surging when flooring it if I didnt have the appropriate tune.