engine light Flashing!

[DRW1000]

I believe the flashing CEL indicates that there is raw fuel going to the catalytic converters (Usually due to a nonfiring cylinder). The flashing is to alert the driver not to ignore it and that damage to the cats can occur if the problem is not corrected. Personally I think you should fix it and not drive it or you may end up replacing the cat(s) too.

[Cavaturbo]

I just used my scanner and it printed out 0304 i check the manual it saids Cylinder4 Misfire Detected. Any ideas where i can go from here now?

[curtis73]

Start checking the maintenance stuff. Pull the plugs and check them for obvious problems. If they all look the same, try rotating them around (remembering where the plugs went) and see if the code repeats itself on #4 or if it follows the plug. Test the plug wires looking for cracks, excessive resistance, etc. If you can find someone with an ignition oscilloscope it will work wonders diagnosing ignition problems.

In all truth I just suggest replacing plugs, wires, cap, and rotor. Those parts should be under $50 and it can't hurt to replace them every few years anyway.

If you check and/or replace all that stuff and it doesn't fix the problem, start looking to fuel issues. Its quite possible that the #4 injector is failing causing a misfire. A competent shop with a fuel pressure gauge can test injector leak down rates and compare. Using the above technique to keep things really cheap you could switch the injectors and see if the misfire follows the injector or stays in #4.

If its none of the above, start thinking about how much oil your car burns. If it burns a noticable amount you may have excessive blowby in the #4 cylinder. A compression test will help diagnose that. If that's the case, drive it with the light on until it dies.

But don't worry. My bet is either a bad ignition component or injector.

When you're trying to diagnose this further, think specifically, not globally. Its probably not the coil, fuel pump, sensors, or fuel pressure regulator since they would apply to all cylinders. OBD2 has a code for that called "random cylinder misfire" when its more than one. Think something that has an isolated event for cylinder 4; cap, plugs, wires, injector, injector wiring, etc.