I want to know what exactly happens in "limp mode" How much power is cut and how is the power cut? I have noticed an odd behavior with my 2011 SHO and I don't think it is full blown "limp mode" but don't know what is going on.
My car's ECM will limit boost to about 5 psi. Timing doesn't seem to be directly impacted, but the Torque readout for wheel hp and torque is down over 100 each. It shifts normal and will accelerate moderately. It just feels like a 300 hp heavy car instead of a 400+ hp heavy car. The only way to correct it is to stop the car, put it in park, turn it off, and then back on. After that "reset" I am back to full power.
This always only happens on my way home from work, not in to work (hotter ambient temps maybe playing a part?)
It is usually after at least 35 miles (I drive about 60 miles one way).
It is only noticeable really at WOT, and there is no discernible moment when it happens. It is not like I am running it hard and it decides to limit boost, it seems to do it when I am cruising and I don't notice until I demand more power.
I can tell obviously, but nobody else not driving probably would.
No CEL's.
IAT is usually around ambient because it seems to happen while highway cruising.
I have seen no correlation to gas, sometimes I put ~3-4 gallons of E85, but will often go several fill ups of straight Top Tier 93.
So is this "limp mode?" I always thought limp mode would be much more drastic cut in power, maybe limited to 2nd or 3rd gear to keep speed down.