P0300 Random Misfire Diagnosis for 2009 Dodge Challenger SRT8 with 60K Miles and Nitrous Mods

I recently encountered a P0300 random misfire code on my 2009 Dodge Challenger SRT8, which has 60,000 miles and includes modifications such as a nitrous system (100-shot setup) along with several minor performance tweaks. After experiencing the issue last night, I've already replaced the spark plugs, checked the battery, and performed a compression test. During testing, I found that cylinders 6, 7, and 8 appear to be misfiring when individual coil packs are disconnected — however, the engine shakes significantly during this process. Switching coil pack locations did not resolve the issue, nor did swapping injectors. I also tested for vacuum leaks with no results and used a noid light to verify injector operation, which showed all injectors are functioning properly. A compression test revealed consistent readings: 180–190 psi dry and 205–220 psi wet across all cylinders — indicating that the issue is not mechanical. Previously, I received a P0308 code intermittently; when I removed the spark plugs, one showed a slightly brown, wet appearance while others were white. The wet plug did not have a fuel smell and may be due to oil contamination or anti-seize compound. I'm unsure of the exact location of the EGR valve (which I believe is in the rear top corner), but no related codes have been triggered. My next step will be checking the O2 sensors, particularly on Bank 2, as I’ve noticed a lean condition there. The issue has persisted for over two days with no clear resolution. I’m looking for cost-effective troubleshooting steps before replacing major components. Additionally, I don’t plan to remove the engine to check timing — any suggestions that avoid full disassembly would be greatly appreciated.