I am getting a p0304 #4 cyc mis fire on my 03 Ram 5.7 hemi

miss fire check coils or plugs

Check engine compression and compare. then test running engine compression most engines have about 130-170 cranking compression and about 90-110 running compression. OR bring that cylinder to its Top Dead Center compression stroke apply air to the cylinder and check to see where the air is going open throttle plate bad intake valve, from exhaust pipe bad exhaust valve, from oil cap piston rings.

Misfire could be a number of things:
a) spark plugs - change them if used over 15K miles - inspect/regap.
b) spark plug wires - change them if over 15K miles - inspect
c) ECM (electronic control module) - test with HEI (high energy ignition) tester.

The vibrating tells me that the engine is running on less than its normal compliment of cylinders - the shaking is produced by the imbalance caused in the engine by one (or more) cylinder(s)
not firing at all.

The "Check Engine" light probably is coming on due the the misfire condition. Go to Pep Boys or
Advance Auto Pats, where they'll tell you (free) your codes causing the "Check Engine' light to be
lit - the code coming from your truck's computer will probably be one or more of:
P0300 - Random/Multiple Cylinder misfire detected
P0301 - Cylinder 1 misfire detected
P0302 - Cylinder 2 misfire detected
P0303 - Cylinder 3 misfire detected
P0304 - Cylinder 4 misfire detected
P0305 - Cylinder 5 misfire detected
P0306 - Cylinder 6 misfire detected
P0307 - Cylinder 7 misfire detected
P0308 - Cylinder 8 misfire detected
P0313 - Misfire detected with low fuel

Misfire could be a number of things:
a) spark plugs - change them if used over 15K miles - inspect/regap.
b) spark plug wires - change them if over 15K miles - inspect
c) ECM (electronic control module) - test with HEI (high energy ignition) tester.

The shaking tells me that the engine is running on less than its normal compliment of cylinders - the shaking is produced by the imbalance caused in the engine by one (or more) cylinder(s)
not firing at all.

The "Check Engine" light probably is coming on due the the misfire condition. Go to Pep Boys or
Advance Auto Pats, where they'll tell you (free) your codes causing the "Check Engine' light to be
lit - the code coming from your truck's computer will probably be one or more of:
P0300 - Random/Multiple Cylinder misfire detected
P0301 - Cylinder 1 misfire detected
P0302 - Cylinder 2 misfire detected
P0303 - Cylinder 3 misfire detected
P0304 - Cylinder 4 misfire detected
P0305 - Cylinder 5 misfire detected
P0306 - Cylinder 6 misfire detected
P0307 - Cylinder 7 misfire detected
P0308 - Cylinder 8 misfire detected
P0313 - Misfire detected with low fuel

P1354VVT System Malfunction (Bank 2)

• P0300 Random/Multiple Cylinder Misfire Detected
• P0301 Cylinder 1 Misfire Detected
• P0302 Cylinder 2 Misfire Detected
• P0303 Cylinder 3 Misfire Detected
• P0304 Cylinder 4 Misfire Detected
• P0305 Cylinder 5 Misfire Detected
• P0306 Cylinder 6 Misfire Detected
• P0307 Cylinder 7 Misfire Detected
• P0308 Cylinder 8 Misfire Detected

Probably bad plug wires. Start there and then disconnect the battery for 5 minutes reconnect and start engine to see which codes have cleared.

mass air and tps would be 2 most common causes.

P0301-P0308....2T catalyst........2004-05 Ram...Cylinder 1-8 Misfire Detected Conditions: Any time engine is running and the adaptive numerator has been successfully updated. When more than 1.5% (300M, Magnum), 2% (Durango, Ram), 2.5% (Durango LEV, Ram LEV), misfire rate is measured during 2 trips, or with 10-30% misfire during 1 trip. 3 good trips required to turn off MIL. Possible Causes: ASD relay output 2 circuit fault Injector control 1 circuit fault Coil control 1 circuit fault Ignition wiring, spark plug, or ignition coil fault Fuel pump inlet strainer plugged Restricted fuel supply line Fuel pump module fault Fuel pressure leakdown fault Fuel injector is damaged or has failed Engine mechanical problems exist PCM has failed. Hope this helps you. Thank You for using fixya.If you like this solution please rate it....Thank You, iluv2fish....Ray

code 300 random cylinder misfire, code 303 cylinder 3 misfire detected code 304 cylinder 4 misfire detected. check the spark plug wires 3 and 4 inline tester for constant fire. also check the spark plugs , clean and reset the gap if necessary. if all is good check the coil terminals for corrosion. if this is all correct then check the coil with a ohm meter for primary resistance by attaching the leads to the positive and negative terminals. then check the secondary resistance by hooking one of the ohmmeter leads to the center terminal and the other lead to one of the outer terminals the resistance for primary test should be 0.95 to 1.20 ohms and the resistance on the secondary side should be 11,300 to13,300 ohms. hope this will help!!!

P0138 (M). O2 Sensor Circuit High Voltage (Bank 1 Sensor 2) ..... P0307 (M). Cylinder # 7 Misfire. Misfire detected in Cylinder # 7.

have a miss fire in 3 and 5 cylinder on a 2005 Ram 1500 4.7 have relpaced coli packs and still does it have a knock in upper engine around miss fire cylinders. what else can i do