losing power and stallin

**jessica lavoy** · 03-05-2010

my gtp sc feels like a crapy 4 cylinder and it stalled twice at highway speed and one time when i put it in neutral it started itself back up??? occasionally ill start it in the morning it shuts off a sec later starts back up and does it again. also the engin sometimes makes a loud knockin noise and when i change the oil it stops. i have an evap code p0440. and had a cyl 4 misfire code that went away. i have replaced: plugs wires pcv, battery, alternater, icm(twice) and coilpacks. today i cleaned the maf. im sure im forgetting about something there is so much wrong. im also gonne replase the crank sensor this weekend-pain in the butt. any suggestions? besides getting rid of it, lol thanks

**blowfishRus6** · 03-05-2010

bad gas milage???

**jessica lavoy** · 03-05-2010

yeah about 18 mpg but i thought that was normal for this car

**jessica lavoy** · 03-05-2010

also i forgot my coolant got low and the low coolant light came on and it was running a little hot. there no signs of a leak. i topped it off the light went off but it is still running too hot.

**1LoudGrandPrix** · 03-05-2010

tstat could have closed for the overheating

**jessica lavoy** · 03-05-2010

ya probably have to check this weekend. ill tell ya today has been one hell of a birthday lol gotte love cars

**1LoudGrandPrix** · 03-05-2010

ya i love the cars and the stereos lol
hope you get it figured out keep us posted
and enjoy your b-day

**jessica lavoy** · 03-05-2010

thanks ill try

**FoSHO99** · 03-05-2010

Did you bleed the air out of the system once you refilled with coolant? It's just that small screw on top of the coolant return elbow/tstat housing.

**jessica lavoy** · 03-07-2010

yes i replaced all coils and yes the coolant system was bleed

**jessica lavoy** · 03-11-2010

so today the ses light came back on code p0440 evap emitions control system malfunction. could this be causing the stalling and the lack of boost power? it seems like the power comes and goes. one min i hit 90mph in a couple seconds and then usually im struggeling to make it up to 60mph? any suggestions?