Check engine light on,code po 300 random multiple cylinder misfire,i replaced the plugs and wires ,its a 98 grand prix supercharged,it runs good except for the engine light,can i reset it?

the sensor to replace is the HO2S sensor which is different to an O2 sensor. (has a different function)
code p0300 is random/multiple misfires
as misfires are from the electrical components you did not pay attention to items like low fuel pressure and faulty injectors which also cause random misfires.

No, a plugged converter would cause the engine not to breathe properly. Too much back pressure would stall the engine or make it run very poorly. It would not be local to any one cylinder-all of them would be affected.

To diagnose a misfire in one cylinder, well, you start at that cylinder. It could be ignition related- the spark plug and spark plug wire for #6, possibly the ignition coil for #6 in the coil pack for the engine. (A v-6 would have 3 coils in the coil pack, one coil for 2 cylinders.) It could also be fuel related, so the fuel injector for cylinder 6 should be considered. And the last reason for a misfire is usually the most expensive repair: low compression in #6. This may be a head gasket problem, or a piston ring problem, or one of the valves for #6 may not be sealing well, causing low compression and the resultant misfire. The engine computer codes a misfire when it senses low power output from that particular cylinder. The misfire causes a lag in crankshaft rotation, and the crankshaft position sensor senses it.

there is a code table here: code table
hope it can help u and good luck

po 300 is random/ multible cylinder misfire detected po507 idle system rpm high-- go to this site for the po507 meaning--www.obd-codes.com/p507 === please go to this site for the po300 code---- www.obd-codes.com/p0300

Random/Multiple Cylinder Misfire Detected have a good day !!

PO300 - Random/Multiple Cylinder Misfire Detected

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crankshaft position (CKP) sensor (POS) signal to vary, Powertrain Control Module (PCM) or Electronic Control Module (ECM) can determine that a misfire is occurring.

Causes:
- Improper spark plug
- Insufficient compression
- Incorrect fuel pressure
- The injector circuit is open or shorted
- Fuel injectors may be faulty
- Intake air leak
- The ignition signal circuit is open or shorted

Solutions:
- Perform Injector Service
- Replace Spark Plugs
- Replace Injectors
- Replace Ignition Coils

The PO300 code is random/multiple cylinder misfire detected. Sinsc you have the code PO302, that means that cylinder 2 is the one misfiring, usually a bad coil pack, or spark plug.

A code “multiple misfire” may mean that one or more of the following has happened:

•Faulty spark plugs or wires
•Faulty coil (pack)
•Faulty oxygen sensor(s)
•Faulty fuel injector(s)
•Burned exhaust valve
•Faulty catalytic converter(s)
•Stuck/blocked EGR valve / passages
•Faulty camshaft position sensor
•Defective computer

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

Google "Nissan OBD II code PO 300." You will get info on what this code means and numerous postings from people who are familiar with this code.

OBD II 300 Random/Multiple Cylinder Misfire Detected

When the misfire monitor detects a misfire, it will trigger the check engine light with the specific cylinder number as the last digit in the P030X code. For instance cylinder 1 misfire is P0301, cylinder 2 is P0302 etc. In this case we have either multiple cylinders misfiring, or the computer simply can't determine the specific cylinder, and as such we are left with the P0300 in computer memory.

Possible Causes:

Fuel injectors, related wiring, sensors and computer issues
Running out of gas, or poor fuel quality
Evaporative emissions system (EVAP) concerns: fuel vapors leaking into engine
Incorrect Fuel Pressure
EGR system concerns: leaking EGR valve or restricted ports
Base engine concerns: low compression, valve train problems and timing issues
Ignition system concerns including, but not limited to:
Faulty spark plugs
Faulty coil or related wiring
Ignition module or related wiring issues
Ignition related sensor faults or wiring issues

P0300 maens random multiple cylinder misfire.
When was the last time the car was tuned.
Check plugs and plug leads are O.K
also check that fuel cap is on tight.