1996 5.7 vortec misfire cyliner 4 and 6

P0300 - Random multiple cylinder misfire
P0301 , 302 and 304 - Cyliners 1, 2 and 4 misfire
P0351 - Ignition coil A primary/secondary circuit malfunction
P0354 - Ignition coil D primary/secondary circuit malfunction

clean the spark plugs

Is #2 injector firing?
Do It Yourself Diagnosis and Repair

Generic OBD II Diagnostic Trouble Codes

DTC CODES P0300 to P0399

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

P0309....Cylinder 9 Misfire Detected

P0310....Cylinder 10....Misfire Detected

P0311....Cylinder 11 Misfire Detected

P0312....Cylinder 12 Misfire Detected

P0313....Misfire Detected with Low Fuel

P0314....Single Cylinder Misfire (Cylinder not Specified)

P0320....Ignition/Distributor Engine Speed Input Circuit

P0321....Ignition/Distributor Engine Speed Input Circuit Range/Performance

P0322....Ignition/Distributor Engine Speed Input Circuit No Signal

P0323....Ignition/Distributor Engine Speed Input Circuit Intermittent

P0324....Knock Control System Error

P0325....Knock Sensor 1 Circuit (Bank 1 or Single Sensor)

P0326....Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)

P0327....Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

P0328....Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

P0329....Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)

P0330....Knock Sensor 2 Circuit (Bank 2)

P0331....Knock Sensor 2 Circuit Range/Performance (Bank 2)

P0332....Knock Sensor 2 Circuit Low Input (Bank 2)

P0333....Knock Sensor 2 Circuit High Input (Bank 2)

P0334....Knock Sensor 2 Circuit Input Intermittent (Bank 2)

P0335....Crankshaft Position Sensor A Circuit

P0336....Crankshaft Position Sensor A Circuit Range/Performance

P0337....Crankshaft Position Sensor A Circuit Low Input

P0338....Crankshaft Position Sensor A Circuit High Input

P0339....Crankshaft Position Sensor A Circuit Intermittent

P0340....Camshaft Position Sensor 'A' Circuit (Bank 1 or Single Sensor)

P0341 Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 1 or Single Sensor)

P0342....Camshaft Position Sensor 'A' Circuit Low Input (Bank 1 or Single Sensor)

P0343....Camshaft Position Sensor 'A' Circuit High Input (Bank 1 or Single Sensor)

P0344....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 1 or Single Sensor)

P0345....Camshaft Position Sensor 'A' Circuit (Bank 2)

P0346....Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 2)

P0347....Camshaft Position Sensor 'A' Circuit Low Input (Bank 2)

P0348....Camshaft Position Sensor 'A' Circuit High Input (Bank 2)

P0349....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 2)

P0350....Ignition Coil Primary/Secondary Circuit

P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
according to this fault codes first mark ignition coils
3 ---------------- 6
2 ---------------- 5
1 ---------------- 4
RB-------------LB
this right banks and left bank, please remove Ignition coils with lids and spark plugs from right bank and swap with left bank, if fault code change as
P 0304 Cylinder 4 Misfire Detected
P 0305 Cylinder 5 Misfire Detected
P 0306 Cylinder 6 Misfire Detected
You can Identify it's a faulty ignition system then next swap ignition lids from ignition coils be careful each coils have two lids one short and other long bit deference and when you remove and fix it to the car keep in mind correct order because each coil two different fire for two spark plugs don't mix up, if you mix it can create the fault code.if you detect any fault ignition coils or spark plugs or lids replace that and also whether god or bad recommend to replace spark plugs, find the right that's most important thing, if this way couldn't found the any ignition fault next step is check fuel presser, when the engine running fuel presser must be around 4.5 bar without engine running must be 4 to 6 bar if the fuel presser too low need to check two different things one is fuel pump other is fuel injectors, in this case you can swap injectors from right bank to left bank and find is the injectors leaking, if not leaking faulty fuel pump.is this information helped you? if yes please leave a comment,

P0171------ system too lean bank#1
Po174------ system too lean bank#2
For these 2 codes, try cleaning the maf sensor (mass air flow), that is mounted in the big black hose that goes from the air filter housing to the throttle plate, if it is dirty, that will cause those 02 sensors to send a signal to the computor to lean the air fuel mixture. If cleaning it doesn't work, the sensors will probably need changing.
P0300---- Random/multiple cylinder misfire
P0316---- Cylinder misfire at start up---- first 100 revolutions.
On those 2 codes, you have to do some testing to find out why there is a misfire.
Possible causes:
dirty/malfunctioning injectors
weak coil pack
fowling spark plugs/wires
Low fuel pressure

Check your bank 2 plugs for colour (do they look hot like they running hot ). Check you EGR Exhaust Gas Recirculation valve (looks like a 80mm diameter spaceship with a vacuum line to the top of it) If this remains closed the engine runs very hot and causes misfire. Possible causes are EGR not opening are 1) perforated diaphragm 2) encrusted valve stem 3) clogged exhaust gas feed pipe. A quick check for function: run the engine and remove the vacuum tube. The engine note should change as the tube is connected and then disconnected. Also pushing on the underside of the EGR with your fingers to lift the diaphragm to open the valve should also result in change in engine note. If its not working just disassemble the EGR and clean with carb cleaning spray, also clean the exhaust gas feed pipe likewise.

this should be the cyliner order and firing order for it.

back of engine

5 6
3 4
1 2

front of engine

the firing order is 1-6-5-4-3-2

look for a vacuum leak

Bank one is toward the front of the vehicle. Sounds like the heated oxygen sensors have gone bad. The Oxygen Sensors are located in the exhaust pipe and require a special socket to remove and replace.