p0304 misfire in 2002 Jeep Grand Cherokee V8

Question

P0304 code... replaced spark plugs, ignition coil on number 4 cylinder, replaced throttle position sensor, added fuel injector cleaner... Still getting a hesitation from 45-60 mph... no fluctuation in RPM... what else could be the problem??

Answer 1

P0304 Misfire number 4 cylinder

Check the sparkplugs , are they properly torque down, and the type of sparkplug , This type of engine has a specific sparkplug requirement. Use the under hood sticker for the type that is required.

 Here are sparkplugs where there was a hesitation at load at acceleration, at idle the ignition analyzer showed no problem,a quick look at the sparkplugs revealed a loose sparkplug the one at the bottom you can see the exhaust mark on the shell.  Cleaned the sparkplug and tihten it properly solved this problem