anyone know what brand spark plugs came in 1999 jeep Cherokee. 4.0 liter. inline 6. I don’t have the owner’s manual or factory service manual.
You should be able to google a free owners manual online, or call jeep and ask.
Champion plug RC12ECC was the original equipment plug.
Champion, like Rod Knox said. Stick with the same ones.
I agree with the Champion choice.
Im curious Why stick with OE? Ive read up on this and many have gone to Autolite
Autolite is a “good” spark plug but no better than Champion or Bosch.
In the long run it is better to stick with the OE plugs. A lot of experimenting might possibly result in finding a plug that performs better but there will be a great many di$appointment$.