Quote Originally Posted by Scott Larson View Post
"Ugly oil" tells me that there is a combustion issue. If you change oil and filter regularly with quality product and you have really dirty oil between changes either there are contaminants entering through the intake or being created due to a misfiring ingnition. That could be anything from a faulty sensor or engine management computer to bad coils or plugs. That also causes carbon buildup on exhaust valves and loss of compression and wasn't that the issue to begin with? Hmmmmmm...we may be getting somewhere Watson!
Scott, thanks for the suggestions. I would REALLY like it to not be a burned/bad valve so keep reading and keep suggesting some options.

See previous post about what "ugly" oil meant to the mechanics (gas in the oil). I change my oil and filter religiously with good filters and synthetic oil. Believe me, baby is well taken care of.

When the misfire code started showing up in mid-May, I swapped coils from one cylinder to the other and the code stayed at #3. I then replaced the spark plug in #3 with a stock Isuzu plug (the same one that were in it from the factory), and the misfire code still stayed at #3. Cleaned the EGR and MAF just to be sure. I also ran SeaFoam through the gas tank, AND sucked some up into the engine via the PCV tube. The engine never smoked like all of the instructions say that it should have after that treatment, but I usually have the PCV replace, EGR and throttle body cleaned at every other oil change.

Maybe I'm missing something, but I think I've been pretty thorough in trying to suss this thing out which is why I brought it to a mechanic, since I had exhausted my limited knowledge.

Any other suggestions/ opinions? I'm open to them all.