I got a 05 Monte Carlo LT 3.8 v6 for $600 with 145000 miles on it. I have replaced the spark wires spark plugs did an oil & coolant change and the intake manifold gaskets with the metal ones because it still had the originals, then 100 miles later the power steering locked up and caused the water pump to leak so I replaced the water pump, the tension pulley, radiator, thermostat & housing, upper and lower radiator hoses, coolant reservoir, radiator cap and power steering pump. I didn't replace the high pressure line on the power steering, so naturally it caught on fire. replaced the power steering again with the high pressure line did another oil & coolant change, luckily it doesn't look like the fire did any real damage. I then replaced the injector in cylinder 6. i had used some sea foam to clean out the fuel system 300 miles before changing the injector to no avail. the cylinder started misfiring after I changed all of the coolant system I did replace the O-rings on the injectors when i did the intake manifold gasket. The small plastic hoses on the fuel rail are damaged, i imagine that's the EVAP code P0443. The Knock code P0332 I'm hoping is caused by the misfire. The blinking check engine light only comes on after I hit 30 MPH and otherwise is not on. I'm planing on switching some ignition coils around to see if the misfire moves and replacing the spark plugs again and getting a compression test. does anyone have any ideas why this miss is occurring. Its been a ride with this fixer upper.

 

Id agree with a compression check to see if its different from its neighbors.

Any smoke out of the exhaust? Wondering if a gasket may be dribbling coolant into it.

Is it firing at all or is that cylinder totally dead?

 

I did a compression test and tested the voltage, all cylinders were within 5 PSI of 180. The voltage was jumping erratically from 11.3 to 13.8 so i changed the alternator and got the ICM bench tested. The ICM was good and changing the alternator helped with the voltage jumps.

It also ate my old belt so i got a new one.

it seems as though it is firing but not all the time

no smoke coming from exhaust but when i put a smooth surface to the tail pipe it fogs up with moisture

It runs decently most of the time with a slight miss but occasionally it will stall out and barely go up hills. it also seems like it stops missing at low RPM's occasionally.

Major gas smell when idling and RPM jumping randomly between 500 to 1200 with the battery gauge loosing half a volt when at 500 RPM

I have tested all the fuses and connectors with a test light and they all seemed to have power running to them

The intake box makes a loud sucking noise when starting and will go away after driving for a bit.

my next guess is a bad ground wire or a major problem with the EVAP system.


Edit: since canging the alternator it went back to a P0306 so I went to the junk yard and got some ignition coils and when i put them on it ran like brand new. I didn't know that the packs can fail on only one cylinder.