Another member { The Maniac } just had same issue and it turned out to be a ignition module. https://montecarloforum.com/forum/of...g-59331/page2/ Post #17 on 2-12-2018 This guy is usually spot on when it comes to electrical

 

 

Get your check engine codes scanned. If possible (depends on the scan tool used), see if you can retrieve the mis-fire data. Those two pieces can usually help narrow these pesky problems.

Given you have done everything ignition system related (plugs/wires/coils/ICM), that usually leaves fueling or air delivery issues. If you have one cylinder with a mis-fire, my guess would be a possible injector (given all the items you mentioned have been done).

Let us know what info you can get and I'm sure we can give you some help.

 

Most auto parts stores will scan it for free, it should tell you which cylinder is has mis-fire and a good scanner will tell you how many times it mis-fired. After that you can check that exact cylinder. Ohm the injector by disconnecting the wire off the injector and put probes on both pins of the injector to get value (example 13.5 ohms) and compare it to another injector or two. These value's should be close to each other and don't have to be exact (example 13.7, 13.3 ect.) Just checked mine on a 2002 Grand prix 3800 with 250,000 and the it was at 13.9 ohm's on a warm engine. If injector is good double check spark plug and if that seems ok try checking compression. Only other electrical part left to blow at it is the crank sensor and I'm guessing that works.

 

I was actually thinking "Crank Sensor" Have put 2 on my car over a 16 year period. Similar symptoms, also had a pretty new MSD coil pack fail, spark would arc out of a breach in plastic body to the block.

 

 

If a catalytic converter is plugged you will sometimes hear a noise such as a whistling noise and possibly that crackle you are talking about usually assoiated with exhaust having to much back pressure . It will also cause a big lack of power under acceleration. A few different way's of testing include doing a back pressure test at the front oxygen sensor, you can remove the front oxygen sensor and test drive and see if there is any difference, you can even put your hand over the tailpipe and feel if it has a lot of air flow when the engine is revved up as it should and compare to another car. As for the fuel filter you should change it regaurdless since you stated it hasn't been done. Good luck and keep us posted.

 

Going through the same crap...replaced EVERYTHING on mine... Still having misfire issues

 

I had the same problem. Mine was a bad plug wire. I am not saying this is your problem too but I could not correct my problem until I ohm'd the wires. I ordered new ones and it corrected my issue. I hope you figure this out.