I have a '99 Durango that I bought used from a dealership a few yers ago and want to do a tune-up on it. I have been reading this forum for a couple years but have a couple questions I haven't found answers for. My Durango has the 5.9. It also has the K&N intake and headers. How can I tell what other mods the previous owner(s) have done? How can I tell if the ignition is stock? I don't have a lot of money to throw at it and it's my only wheels, so I can't just tear it apart and work on it for a few days. I do think the plugs are due to be changed and assume that the ignition that's in it is going to have bearing on what plugs I should have. Any suggestions would be appreciated.

 

if you think you have a performance ignition simply pull one of the plugs out and see what it is, replace it with the same part that is in there, other than that just have to go look for the other mods and identify them, if the coil is not stock it should be marked with a band/model, look it up and see if its a stock equivilant or not.