I had the same problem in my 99 firebird....check the engine module or it could be the coils mine was both along with a faulty catalytic converter..if you smell a rotten egg then its the cat... goodluck
Check the current at the fuel pump; fuel pump might be going.
TRY THE O2 SENSORS HAPPIN TO MY 1996 IMPALA TO BUT THE WIRES WERE CROSSED ON MINE
P0300 Diagnostic Code - Random Misfire
Symptoms.
Engine may stumble or miss
Engine may be hard to start
you may notice no issues
Cause
Failing spark plugs or spark plug wires
Bad coil or coil pack
Failing oxygen sensor(s)
Bad fuel injector or more than one
Stuck exhaust valve
Bad catalytic converter
EGR valve or valve passage clogging
Bad camshaft position sensor
Bad PCM or ECM
The Fix
Best first action is a tune up, new plugs, wires, inspect all hoses and wire connections then reset the code. If it returns you will need to narrow it down to a system, coils and coil packs should be tested, catalytic converters for function ( do you smell rotten eggs?). A misfire that jumps cylinders could indicate a lean condition, do you have any other codes along with the 300? this will help clue you in to the source, check valve function to make sure they are opening and closing fully.
This is probably pone of the most difficult codes to troubleshoot, so start with the basics and work your way into the more expensive options, in many cases a good old tune up solves the problem, back it up with a fuel system cleaning and see where you stand.
Doubtful. Bad spark plugs would give you a rough idle, hesitation and poor performance. And they may also give you a P0300 code for random misfire.
Code P0300, Intermittent rough idle,
Well...the misfire on 1 and 3 would explain the rough idle. The misfire could be from worn plugs, wires, bad coil, or bad injectors.
If it is slipping in gear or any out of the ordinary rough shifting.
Check the Park Avenue EGR valve for a clog. A clogged valve can cause a rough idle and stall at a light.
Old spark plugs can make a car misfire, run rough, and not fire at all.
Misfire? Due for a tune up? Check engine light on?
Check idle adjustment (rpm) then check timing, then check for misfire-start there.
P0300 Diagnostic Code - Random MisfireSymptoms.Engine may stumble or missEngine may be hard to startyou may notice no issuesCauseFailing spark plugs or spark plug wiresBad coil or coil packFailing oxygen sensor(s)Bad fuel injector or more than oneStuck exhaust valveBad catalytic converterEGR valve or valve passage cloggingBad camshaft position sensorBad PCM or ECMThe FixBest first action is a tune up, new plugs, wires, inspect all hoses and wire connections then reset the code. If it returns you will need to narrow it down to a system, coils and coil packs should be tested, catalytic converters for function ( do you smell rotten eggs?). A misfire that jumps cylinders could indicate a lean condition, do you have any other codes along with the 300? this will help clue you in to the source, check valve function to make sure they are opening and closing fully.This is probably pone of the most difficult codes to troubleshoot, so start with the basics and work your way into the more expensive options, in many cases a good old tune up solves the problem, back it up with a fuel system cleaning and see where you stand.
you have a cylinder misfire
Check engine light is on with a misfire code, rough idle, lack of power, low compression.
If it is slipping in gear or any out of the ordinary rough shifting.....
P0300 Diagnostic Code - Random MisfirePo303 Diagnostic code - Misfire cylinder 3Symptoms.Engine may stumble or missEngine may be hard to startyou may notice no issuesCauseFailing spark plugs or spark plug wiresBad coil or coil packFailing oxygen sensor(s)Bad fuel injector or more than oneStuck exhaust valveBad catalytic converterEGR valve or valve passage cloggingBad camshaft position sensorBad PCM or ECMThe FixBest first action is a tune up, new plugs, wires, inspect all hoses and wire connections then reset the code. If it returns you will need to narrow it down to a system, coils and coil packs should be tested, catalytic converters for function ( do you smell rotten eggs?). A misfire that jumps cylinders could indicate a lean condition, do you have any other codes along with the 300? this will help clue you in to the source, check valve function to make sure they are opening and closing fully.This is probably pone of the most difficult codes to troubleshoot, so start with the basics and work your way into the more expensive options, in many cases a good old tune up solves the problem, back it up with a fuel system cleaning and see where you stand.
If your check engine light is blinking that means an ignition misfire has been detected
0303 Cylinder 3 Misfire Detected Could be a bad plug or plug wire; or an injector problem. Is it running rough? If it sounds smooth, it could be a transient condition. Such as driving on rough roads or lugging the engine, however rough roads/lugging will unlikely set a misfire code with an automatic transmission. I'd give the light several days and see if it goes out. If it's running a bit rough and it's time for plugs and wires anyway you may go ahead and do replace them. Once it's running smoothly, the light will go out soon--three consecutive ignition cycles without a fault. The way it sets a misfire code is the computer checks the crank position sensor every 100 revolutions for any deceleration that a misfire would cause. If it discovers deceleration, it looks at the cam position sensor in order to identify the cylinder. Therefore the PCM may not detect a light misfire right away. If it detects a severe misfire, it will flash the MIL, since a severe misfire could damage the catalytic converter, and disable the lock up torque converter clutch momentarily to rule out the rough road possibility. Since this code is not set by an actual lack of spark, just unexpected engine deceleration, any action that jostles the engine will be read as a misfire.
The rays of light from the object are reflected off rough surfaces in "random" directions and so do not form a coherent image.
Have it checked for codes. There will be a misfire code that will let you know what cylinder has the problem.
My car did the same thing So I hooked it up to a computer come to find out it was 2 oxygen sensors that went bad.
My idle was running rough and slight loss of power (5 cylinder engine). The power loss is more noticeable on cars with less cylinders.
When light strikes a rough surface it reflects in essentially random directions.
A probable reason can be that when the surface is smooth , the normal vector is straight up and ball bounces . But when the surface is rough , it has random inclinations at different points and hence , different normal vactors act in random directions and cancel each other out.
Misfire is caused when a cylinder doesn't ignite its fuel mixture. Suspect a bad plug, coil, or wire. This will not be caused by a mass airflow sensor, that can cause a rough idle or bad fuel economy, but will not cause an individual cylinder to misfire. Driving with a continuous misfire condition will eventually destroy your catalytic converter. If your check engine light is flashing you are doing serious damage to your cat converter.
There are many things that can cause a rough idle on this car. The computer could be going out, the engine may not have enough oil, and the engine may not be getting enough fuel or electricity.
When you drive with a bad fuel injector, your engine will often misfire. You might also have a rough idle and increased fuel consumption.