Miss fire in cylinder 1 and 4

year/make/model??? Check injector for operation. If ok, do a compression test to see if cylinder is good

you don`t say how you verified that the plug and wire was good. I think these use coil on plug, if so check powers and grounds for that coil as one may have a problem.other things that could cause this is a bad fuel injector, poor compression due to either rings, valve, worn cam, damaged push rod,

possibly wiring harness fault,sesor wheel installed backwards or an even fire/odd fire engine mismatched components

Try moving the coil pack from cylinder 1 to another cylinder (swap locations) and see if the same code comes up. If code is different, then coil pack is bad. Other reasons for miss; bad injector, poor compression.
Also, I know you changed plugs already, but always use AC Delco 43-103 plugs on this vehicle.

first do a cylinder compression test on engine to verify good engine compression this should be around 110psi to 175 psi check for vacuum leak, intake port for #6 cylindermay be leaking air, or also check coil for that cylinder, if wire and spark plug have already been changed, last replace fuel injector for that cylinder.

Could only be a few things. The coil #1, Fuel injector #1, Stuck intake or exhaust valve, or blown head gasket allowing coolant into cylinder #1. Use a spark tester to check the spark coming out of cylindr #1 if checks good then ohm test the injector when it is warm. Check other injectors to compare. Do a compression test on cylinder #1 and test other cylinders to compare. If cylinder is low compression suspect valves and or head gasket. If compression is low then het a leak down tester to test if a valve is broke or sticking. On your sable i would suspect injector or coil most likely.

you may need to perform a leak down test to the cyliner and maybe you may have carbon on that valve. make sure the new spark plug wire has the correct continiuty

First check plug and make sure the right plug for this vehicle,make sure that the heat rating for this plug is correct. Your problem could be a wrong heat rating plug been installed. Also make sure that the misfire is due to a bad plug and NOT a bad injector or injector wiring or uneven compression or even bad coil. Check injector wiring and make sure it not shorting or broken. To check injector pulse use a NOID light can be bought at almost any auto parts store like Auto-zone etc. Also compression can be checked with compression guage. A rule of thumb to go by is if any cylinder has more than 10 PSI in difference in compression there is a problem like a burnt valv etc. Here is a n example cyl# 1 170psi cyl#2 176 psi cyl#172psi cyl# 4 150 psi, there is a problem with cylinder # 4 and will cause a miss from cylinder #4. Good luck and thank for using FIX YA

Check compression on engine and if that's good then check injectors(may be bad) . The key to use when checking compression with a compression guage is NOT have your reading be more than psi difference between cylinders. For example is cylinder #1 is 150 psi and cylinder #2 is 172psi then there is a problem like a burnt valve or something . From my experience these types of misses usual come from bad plugs, wires or bad injectors. Good luck and thanks for using FIX YA

If you have coils and spark plugs then you don't have wires. From personal experience these car's misfire because of coils and BAD INJECTORS. If you replaces coils and sparks plugs you need to check injectors. Get a NOID light and check injectors pulse to make sure it good. First you must locate the cylinder that has the misfire/Missing,this can be done by using a computer/code scanner or if can be manually by disconnecting each coil and see when there is NO change in idling or shaking. What you are looking for is when you disconnect the Eugine should shake more and when you reconnect it would smooth en out. If any cylinder when disconnected the engine doesn't change that the one with the problem. Check again for spark and make sure it good. Then check that injector pulse plug off injector connector and connect it to NOID light you should get a constant flickering of NOID LIGHT. If you do then BINGO that injector is BAD. However I must say this test is on valued if you have performed a compression test on all cylinders to make sure there are no BAD/Burnted valves. This can be done with a compression guage remember the reading should NOT be more than 10PSI difference between all cylinders example of a normal reading is cylinder 1 170 psi cylinder 2 168 cylinder 3 172..... abnormal is cylinder 1 170 cylinder 2 85 cylinder 3 172 ...etc. I know this is alot of info but read through and follow these step and you'll be ASE certified by the end of this job. Good luck and thanks for using FIX YA