Number 1 cylinder missfire. What to do?

[k_y86]

My number 1 cylinder is missfiring. Already chnged the coil pack. Car is already at 100000 miles. Spark plugs were changed with the bosch 4+ about 40000 miles ago. Fuel filter was replaced 30000 ago. Emptied a bottle of fuel injector cleaner into a full tank of fuel and the engine light continues to light up. Can somebody shed some light on this situation; do I need to replace the fuel injectors or is there a vaccum leak of some sort.

[RawAmericanMuscle]

Can you enlighten us on what has been done to the car as far as mods?

[Spacey_stacey75]

REplace fuel injector for that cylinder, make sure to change the o-ring and replace you MAP sensor.
Should fix it, just had same problem with #3 cylinder.

[bryson87]

Check the gap on the plugs

[cobalt123]

definately check the gap on the spark plugs first cheapest way

[Revenant_SS]

Swap #1 and #4 plugs. Chances are you'll get the misfire on #4 now because Bosch plugs are pure garbage. Replace with a set of AC Delco or NGK.

Put it to you this way. If I have a customer coming in looking for a tuneup, I would send them to another shop before we'd put Bosch plugs in.

[bryson87]

and if swaping the plugs dont work. swap the coil packs around also if it moves to the next cyl you put it on its the pack

[k_y86]

Originally Posted by KRSPerformance Can you enlighten us on what has been done to the car as far as mods?

No mods have been done to this car just stock.

---------- Post added at 09:20 AM ---------- Previous post was at 09:18 AM ----------

Originally Posted by bryson87 Check the gap on the plugs

Can not gap the spark plug because it has the 4 of the things that you need to gap, not just one.

---------- Post added at 09:22 AM ---------- Previous post was at 09:20 AM ----------

Originally Posted by Revenant_SS Swap #1 and #4 plugs. Chances are you'll get the misfire on #4 now because Bosch plugs are pure garbage. Replace with a set of AC Delco or NGK. Put it to you this way. If I have a customer coming in looking for a tuneup, I would send them to another shop before we'd put Bosch plugs in.

Already swaped spark plugs but with the #3 cylinder and it's still running the same.

---------- Post added at 09:25 AM ---------- Previous post was at 09:22 AM ----------

Originally Posted by Spacey_stacey75 REplace fuel injector for that cylinder, make sure to change the o-ring and replace you MAP sensor. Should fix it, just had same problem with #3 cylinder.

Dude I think your right because so far I've swaped the spark plugs and nothing so far. So where would the MAP sensor be located on a 2007 LS cobalt.

[Spacey_stacey75]

well mine on an 06 was right under the intake, I think above the intake manifold

I went and bought the haynes repair manual so I could do this shit myself. I hate paying someone for something I can do.