Running rough after a fillup
It stutters and hesitates on acceleration. Sometimes it's hard to start. When I test drove it, it was easy to get up to speed (while still hesitating occasionally), but my wife said after she drove ~12 miles it barely had enough power to make it into the driveway.
CEL is on. I checked the codes, and got 3 cylinder misfires. I cleared the codes and drove it the next day, got 3 more cylinder misfires (not the same cylinders as before), and lean condition on banks 1 and 2.
I took it to a shop. They said "it has several misfires, but cylinder 4 is definitely dead. We can replace the coil and 2 spark plugs, it'll be $850." I asked about the lean condition, he said "yeah that's weird you'd think it would be rich" and left it at that.
I feel comfortable replacing coils and plugs myself, done that plenty of times on other vehicles. But I'm not convinced that's what it needs. Any help is appreciated.
edit: I didn't save the first 3 misfire codes I had, but this is what showed up the next time I drove it for 5 minutes:
P0171
P0304
P0307
P0300
P0174
P0306:
Edit #2:
the shop got misfires on cylinders 4, 7, and 8, and they say "the coil, ignition wires, and spark plugs are dead on cylinder #4".
Last edited by oakback; Jun 25, 2018 at 05:05 PM.
If the fuel injectors aren't too difficult to reach, I'll check to make sure they're ticking while the engine is on. On another vehicle, I once had a misfire that ended up being a bad fuel injector. To confirm, I used a long socket extension, touched it to the injector, and put the other end against my ear. Cheap stethoscope.
Meanwhile I'll research to see if there's a way to check/test a coil with a multimeter. Also I'll try swapping the coils on misfiring cylinders with coils from non-misfiring cylinders, and see if the code changes as well.
After exhausting the free options, I'll change the fuel filter, since the misfiring is on multiple cylinders. Maybe do spark plugs too. Then move on to replacing coils one at a time.
Let me know if my plan sucks.


