A 2006 Forenza. Was going down road and heard a sound like something came loose. Car atrarted to lose power. Then slowed and stalled. Now car will turnover but not start. Battery is good. Have spark from wire boot to plug. Seems to turnover a littlse slow.What do you think? Help!!!

You have a power wire rubbing the chassis somewhere in the harness that when it slightly touches metal the voltage drops and causes the flickering and will make the computer act up. Finding exactly where the short is occurring will be a tedious and time consuming inspection of the wiring.

polo Forenza.
what is that.?
are you posting German, cars to a Korean car, Forenza.
or is this a big time custom swapped car.
we can't guess./?

the engine stalled.
for sure.
all cars can stall, all vehicles.
the top key clue, is
RPM 0
CEL glowing.
and zero engine sounds.

its supposed to, with an automatic.
my guess, is its doing something strange, so ask someone
to drive your car, a that can explain the symptoms.
here is a typical list of symptoms. your FSM covers each.

http://www.fixkick.com/tranny/slush/symptoms.html

is your checking light glowing running? yes, scan it.
is the transmission Driver lamps flashing odd>, yes, scan it.

scan it. (all answers are USA ,unless you break spades... and... tell.
this car is throttle by wire. and is weak as a cat. like that.
for justabout any reason TBW will go to limphome mode.
connect any OBD2 scan tool to the 16pin underdash, DLC connector
and scan it. report all the TDC.
also the check engine lamp, may glow. CEL glows running?
ignoring that?

you cranked the battery low.
ever do the 60k tuneup on the engine? with timing belt, per operator guide?
if not BOOM !

which engine in this Daewoo/GM-Holden/Suzuki wonder box.
what country was it sold to.?????? usa, ?
did you use a scan tool cranking (battery charged) to see if you get
ERRORS?

if car is a USA car, IS IT?
it has (wiki quote)
The US model line features the 2.0 L four-cylinder E-TEC II made by General Motors, developing a maximum power of 132 horsepower at 5600 rpm.

this engine is listed as INTERFERENCE.
and as such bends the head valves over with the timing belt fails.
its luck thing, like walking cross street blindfolded..
some make it.
here is what you forgot, see cam timing parts... here.

http://navigates.gates.com/Parts.aspx?Year=2006&Make=Suzuki&Model=Forenza&Engine=4-Cyl.+2.0+L&Class=Passenger+Cars+%26+Light+Trucks&Type=Passenger+Cars


all comments based on USA GM engine.

Have the fuel pressure tested, running out of gas will destroy the fuel tank moumted fuel pump or cause it to run slow with the resulting loss of power.

So your saying the car stalls out at a light.
Does this happen at all speeds or speeds above 45mph's? If it happens at all speeds probably not transmission related . But if it happens at speeds above 45mph's sounds like brake light switch not disengaging Torque converter clutch solenoid (TCC solenoid).

check the vehicle knock sendor, are u using the right grade of gas, and oil for u temp zone

They have been doing well and there problems are fewer than most. Sounds like you have a pretty good car. Have those trouble codes checked and repaired though so it does'nt cause problems down the road. Good luck.

I doubt u are "loosing compression" more likely a sensor failure is causing a loss of power, go to any Kragen or Autozone and have them run a OBD 2 trouble code test, it is free, then post the code back here.