I have a 1997 Saturn Sl2 that's throwing a code for cylinder #4 miss fire and code for EGR insufficient flow.

While driving the SES light will flash the entire time the car is running and it bucks and stutters and has little power when RPMs are low but seems to run a bit cleaner when RPMs are above 2000.

So far I have replaced the ignition wires, plugs, coolant temp and EGR valve. Today I am going to try the clean the EGR intake and exhaust ports which I have seen on here to be a common problem. My plan was to use a Bass String (Decent diameter steel wire tightly wound around another wire) and a drill on reverse to work like a snake to really bore out any carbon build up then run the engine for few moments to blast everything out of it.

Do I need to be worried if I continue to drive this car its my only running vehicle and I just started a new job that I cannot miss. I don't have much to spend on parts right now so any trips or tricks I can do that wont cost much would be GREATLY appreciated!

Any other

Any other things that I can check would be greatly appreciated. I started a new job recently so I'm strapped for cash

 

Did you check the compression? If the compression is good move the #4 injector to another hole and see if the misfire follows the injector.

 

I'm in agreement with Andy. BUT, I'm lazy and I would just try swapping the #1 and #4 spark plug and wire to see if the code moves. If that doesn't make a difference, then I'd swap the injectors.

 

Going out on a limb here, tell me if I'm right:

Between 150-200k on the engine
Misses at idle (ses flashing at idle)
Runs with a pretty good vibe you feel in the driver's seat
You are also getting a camshaft sensor error
You may be getting a p0030 random misfire but likely only a p0304 4 misfire cylinder 4. And the cam cam code.

Make sure you have spark at #4. When you pull the plug to do the compression test, if it is soaked in oil, that is likely the cause of the misfire but the nature of the true problem is significantly more serious.

I would not use a bass guitar string in that port. Carb choke cleaner spread evenly on the internal surfaces and allowed to soak as much as possible although it just keeps running further and further down usually does the trick for me. Just keep in mind that all of what you are spraying in there is combustible and you don't want a huge mass of combustible material to combust all at once. If you are using significant amounts, let it soak, then put a towel over the output unless you like cleaning up scuzz oil mess. Wear hearing protection and warn any neighbors that are ******** that you will be making a racket.

Start the vehicle which will be difficult because i it behaves as though it is flooded so hold the gas pedal down all the way, then pump It to get it to turn over. Feather the gas pedal until it stabilizes on its own. Make sure the towel is not resting on any moving parts nor will it get thrown there. Best to have a buddy mind the towel.

If the SES is flashing even at idle, you likely have a dead Miss on number 4 probably an exhaust valve. I don't know that anyone has posted about an S car injector just flat-out going bad in the 14 years I have modded this forum. But anything is possible and good troubleshooting involves taking everything into account. Please let us know all of the codes you are pulling