After engine has completely warmed up (15-20 min of driving)the car****** very roughly at the 22mph mark. The RPM gauge also revs at the same time. This will only happen if I am accelerating. For example, if I take my foot off the gas and let the car coast over the 22 mph mark, it will not*****. A free computer scan gave a code of P0304 cyl 4 misfire. Any ideas?
Saturday, January 8th, 2011 AT 4:12 PM