Cylinder 2 misfire - probably spark plug or wire

The code 300 is a Random/Multiple Cylinder Misfire....a 302 is Cylinder # 2 misfire detected. ..and the same for 304 and 306..being 304 is cylinder 4 misfire and 306 is cylinder 6 misfire...All these at the same time normally is a faulty coil pack..,and or faulty coils...spark plugs.,plug wires.....It should be running horribly or barely ....However it could be internal losing compression.....It could just need a good tune up.....Disconnect battery before changing coils,wires..,or plugs in order to clear the fault codes.....

PO300 and P1399 are random cylinder misfire detected.
PO301 cylinder 1 misfire
PO302 cylinder 2 misfire
PO304 cylinder 4 misfire
PO306 cylinder 6 misfire
I would say that you have damage to the ignition wiring harness or you ECM is failing.

1) Google the code with the car model; read the troubleshooting tips
2) replace the spark plug on 3 cylinder if worn out;
3) need to check the el wire condition which supplies el to cylinder 3 - might need to replace the whole wiring el . Package...
4) erase the code once the parts are replaced.

it will be better to replace all spark plugs at once

Be safe when working on el .parts

Code indicates #2 cylinder misfiring. try swapping wire from another cylinder, clear codes and see if code for other cylinder comes up, if so bad wire. ignition coils were common to crack in those years as well...taht would be the most frequest issues...hope this helps ya

It means that #2 cylinder is not running right. It could be a bad spark plug, bad spark plug wire, bad injector, or bad coil pack. You will need to find out if you have spark on that cylinder. If you have spark, then you will have to check to see if it is getting fuel properly. This could also include a bad valve in the engine. If the compression is not right the cylinder will not fire either. I hope this helps you.

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

A flashing Check Engine light means you have a ignition Misfire, start by replacing the spark plugs and spark plug wires, one or more is defective. If you have a electronic engine control fault code reader the cylinder or cylinders that are misfiring will set a fault code, the codes are P0300-P0306, the last number being the number of the cylinder ( cylinders 1-6) the computer has detected a misfire in.

mass air and tps would be 2 most common causes.

you will need to check #2 cylinder compression. If good run engine and unplug the fuel injector for #2 to see if the idle changes. no change means bad injector. also check for good spark at plug.


possible intake manifold leak.

#1 plug is the 1st plug on passenger side by firewall