I need help ASAP, I just started a new job and have no other car at the moment to drive, The car sounds fine and drives fine, I just got a new Walbro 255 installed and a tune... Car was fine after the tune and now a few days later, Im getting those codes. I have FIC 1100 injectors, FP Black and full bolt ons. I just switched out my Aeromotive 440 for the walbro cause i did not wanna rewire the car right now since i am on a stock block and not even pushing the 255. The light came on while... Backing, stopped, Put the car in 1st gear drove about 100ft and the light came on.. Here is a freeze frame.. But i need to get to work tomorrow morning... Is the car even safe to drive if i dont boost or beat on it?

Freeze frame information:
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Engine Load = 30.98 %
Engine Coolant Temperature = 83 °C
Fuel Trim Bank 1 Short Term = 0 %Fuel Trim Bank 1 Long Term = 3.906 %Intake Manifold Pressure = 6.237 psiEngine RPM = 1,042.75 rpmSpeed (OBD) = 0 km/hTiming Advance = 9 °Intake Air Temperature = 44 °CMass Air Flow Rate = 5.4 g/sThrottle Position(Manifold) = 12.941 %Fuel Level (From Engine ECU) = 98.824 %Evap System Vapour Pressure = 65 PaBarometric pressure = 14.649 psiVoltage (Control Module) = 14.135 VEngine Load(Absolute) = 25.882 %Commanded Equivalence Ratio = 1 Relative Throttle Position = 4.706 %Ambient air temp = 44 °CAbsolute Throttle Position B = 13.333 %Accelerator PedalPosition D = 19.608 %Accelerator PedalPosition E = 9.412 %
End of report.

 

Isn't that just a cylinder 4 misfire?

 

Yes... But i have no idea whats causing it... and i need to drive the car tomorrow and dont wanna blow something up

 

p0304 - cyl4 misfire
p0300 - random cyl misfire

Check your spark plugs make sure they are gapped properly or even change them, make sure your pump is woring properly and you got enough fuel coming in...do you have an a/f ratio gauge?

 

If it keeps coming back, then I wouldn't drive a long distance because raw fuel might be getting to the cat, but if it's just an occasional, random event, there's no problem driving around calmly. Check the plug wires and every connector you can see, including the injectors, clear the code, and try to be cool.

This is exactly why I have a $30 code reader in my glove-box. To verify that it's nothing big, clear it, and move on.

edit: years of owning a DSM helps keep you calm; when the CEL isn't lit in one of those, the first thing to check is whether the bulb is burned out

 

Yeah i have a bluetooth adapter for my droid for torque app.. and thats how i got the info.. and yes i have a AEM a/f gauge. Everything seems fine.. Just threw that code..

 

So true, if the cel isn't on, that's when I'm worried

 

Switch coil packs from cyl 4 to another cyl. Clear the code and drive to see if it comes back. If it does come back,but on a different cyl then bad coil pack. If it comes back on number 4 it could be injector.

Also pull plug and check it for foul or broken tip.

Lastly I've heard of lightweight flywheels and aftermarket clutches popping this code from time to time.

I'd check the above but clear the code and see if it pops e code again.

 

check your injector clips especially if they are the plug and play ones. They gave me missfire codes until I depinned and soldered them.

If you rule out the clips time to boroscope that cyl 4. When I had a cyl 4 missfire pop up consistently I had a chewed up piston in there. good luck!