c5racr1

iTrader: (1)

I have an 04 Ctsv and every now and again I will give it full throttle and immediately get "reduced engine power " mode. What causes this?

2001NBMZ28

Maybe torque management? Just a guess.

foff667

iTrader: (2)

Any codes present? do you have a forced induction application?

c5racr1

iTrader: (1)

no codes and no forced induction. last time it happened i was in 3rd gear and went to WOT, car "bucked" and went into reduced power

foff667

iTrader: (2)

Weird, any TSB's from GM for your vehicle for this issue? Doesn't sound like something you'd want to "tune out" in this case & sounds like a mechanical issue of some sort.

c5racr1

iTrader: (1)

let me tell you the whole story, It has a crate motor LS7, 24X reluctor ring to use the stock PCM. it has been running fine for 2 years and now it is starting this. make any more sence now?

foff667

iTrader: (2)

Sounds like a mechanical issue of some sort, vehicles don't just go into REP for no obvious reason

jimmyblue

iTrader: (11)

From my limited understanding, this is a fault mode
that is entered when the PCM doesn't know what to
believe, between the various airflow estimates and
thinks maybe the throttle position is out of control.
So it limits max angle. You have a MAF, the speed
density and an alpha-N estimate and I recall seeing
"stuff" about it involving more airflow than the
TPS @ RPM "ought" to permit. Like if you went and
put a cam & decent exhaust on it, you might tune
up the speed-density part of it but the alpha-N is
just a "dumb check" and maybe all you have to work
with is error limits. I know I've run across this on
either a Corvette or a DBW truck but it's been too
long to remember. Anyway, try rooting through the
Engine Diagnostics (not DTC list, but the limits you
can fiddle) looking for stuff about "airflow error" and
see if you have any immature codes for what you
find.

I bet the Helm manual might have a decent explanation,
I only have F-body books.