Hi... i am a little confused... my truck does not want to start when the temprature outside goes below minus 6 celius i have had code po339 and po300 i changed the cam sensor.But i still getting code po339. I am also only getting 10.5 miles to gal, new plugs wires coils K&n air filter cleaned out the throttle body and cleaned the iac sensor use fuel injector cleaner / my question would be could the knock sensors be causing these problems as well as the crankshaft positioning sensor

 

when did you do all the tune up work, after you noticed this starting problem or before?

 

At minus 6 would you want to work? LOL

Seriously though, do you have a block heater? A garage?

P0300 are generic misfire codes.

P0339 is the crankshaft sensor. Im not sure why you replaced the cam sensor but try replacing the crankshaft sensor.

Also, knowing the year of your truck helps in the future so add it to your signature or profile

 

Yep, crankshaft position sensor P0339. Try changing that out, and getting a block heater installed.

 

Ha, try moving South nobody should live where it gets that cold.

Sorry couldn't help myself.

 

well i did all the work in the last 6 months the truck is an 03 5.7 . it has a block heater , no garage i replaced the cam sensor is what i was told to do first it did get rid of po300 i will try the crank sensor now / never had a problem last year and it was colder what about the fuel consuption? thanks

 

I had the same question about the fuel consumption...you're pretty close to the norm. Like HammerZ71 told me, with a cold air intake, the cold temp outside, winter gas, that's what the Hemi's do in the cold weather....I checked my OHD, and my average MPG is 9.5!! So, 10.5 isn't all that bad. As for the starting issue, maybe someone else will chime in. That's out of my knowledge capacity!!

 

is your mpg hwy or cty mine is cty 10.5 cty 13 hwy

 

City 9.5

 

lower MPG in winter is somewhat normal due to the the winter fuel blend. However, normal maintenance things like tire air pressure, plugs and wires, air filter, ECT, all playa factor in MPG. You can also reset the PCM to make it relearn your driving habits and erase fuel trims stored in the PCM