03 Malibu random cylinder misfire 3100v6

Hi all,, My first post ,, I have been reading for days and have not seen anything with my same problems Have an 03 malibu 3100 v6 ,74000 miles This problem comes and goes, Start car and idles and starts as always, very sluggish driving, seems like 2 cylinders will kick in as the rpm picks up and then comes and goes.. Did not have a check engine light on for about 3 weeks,, Finally last night one came on and Autozone stated random cylinder misfire,, Pretty broad area, as they told me. I have changed Ign coils, plug wires ,spark plugs(gapped at .060). Fuel filter and have ran many bottles of dry gas and fuel injector cleaner, (lucas in fuel as of last night). I am not loosing any fluid, Oil , antifreeze,, etc. The dealers in my area told me there is nothing really they can do , that I did not do , without a check engine light on. Car has ran good about 200 of the last 400 miles. Any suggestions would be very helpful and thanks in advance.

I have the Same issue on a 2002 Malubu. First was the P0113 code. replaced the IAT sensor and the wiring harness and the Mass airflow sensor. then started throwing the P0300 "multiple random misfires" code. I changed Plugs and wires. Light went away, Still runs bad and sluggish.

Its at the Dealership now, they updated the PCM, and are running fuel preasure tests at the moment. Ill keep you informed with what they find. Let me know if you find the ghost.

Thanks for reply,, I took it to a local shop to have the exhaust checked(cat convertor) to be exact.. They told me that they unhooked the exhaust and the car ran perfect.. so they are telling me I need a new exhaust system, that the cat fell apart inside,, 650 dollars to replace all.. I checked with my local dealer and they told me the convertor is warrantied until 80,000 miles but they also would have to replace rest of exhaust. and with their labor rate it would be over 600 dollars, what a crock of ####!!! I cant believe what it cost to put an exhaust on.. supposed to get car back today or tomorrow.. Lets hope its fixed..

It sounds like you have it under control but let me add this to help any other readers with a P0300.My first step after a visual inspection is to pressure clean the injectors,it works 99% of the time on GM cars.Also you should use Top Tier rated gas decause it has extra detergents to prevent clogging.Good luck!

Are there special tools needed to pressure clean the injectors?? Or is it something that the dealer can do.. or can I do myself?? thanks

Exhaust seemed to have fixed the car... At least that is all that they told me they did.. Car runs fine..