Hi please can somebody help me please ive recently bought a Fiat brava as my 1st car it only has 50.000 on the clock and ive recently had a head gasket repair wish seemed to be fine be 2 days later i been seeing Engine management warning light up on the dash. Ive had a diagnostics computer plugged in to the car and was give 4 codes as follows :-c300 c302 c304 which i been told means cylinder 1,2 & 4 are all miss-firing ive had the coil pack changed and for like 6 miles the car was fine but after that the rattling/ shaking came back when am in low gears and get to about 3000 revs this starts and when stationary at lights it rattles quiet a lot. please can somebody help me to what the problem ?? [/code]