Hello everyone. I am new to the forum so please forgive me if this issue has already been discussed. I have a 2000 Escalade with about 140k Miles. Always been a great running vehicle since I bought it about 6 months ago. Recently I started noticing a misfire under load while climbing a hill with speeds between 60 and 70mph. After the misfiring and vibrations which are very noticeable the ses light illuminates and when checked with a scanner reads the p0307 code for misfire on cylinder 7. After it happened originally I replaced plugs, wires, cap, and rotor, I could definitely tell an improvement in performance after the tune up but the misfire was still there. Next thing I tried was running some seafoam in my gas to clean up any bad fuel that may have contaminated the system. Still no luck misfire still there. Last night I replaced the crankshaft sensor, thought that did the trick and then today(on the same hill as always) the misfire happens again. I am so tired of trying to figure out what's going on. I'm at a loss. Any help would be greatly appreciated. Thanks in advance.