Had a 3rd cylinder misfire. Changed the coil pack
on that cylinder. Ran great for two days. Started
back to idle rough & check it engine light flashing
when driving. Changed the spark plug on the 3rd
day. Runs good but, idles rough when you start &
stop. My next thought was fuel so, I bought some
Seafoam fuel conditioner & added it to 1/4 tank of
gas. My old lady has driven the car back forth to
work the last two days but only 5 miles round trip!
So my question is, do you think if I drove the car
on the highway for 30 miles or so that should help
right? And if not, what will?
Possible causes; Faulty spark plug 3, Clogged or faulty fuel injector, 3 Faulty ignition coil 3, Fuel injector 3 harness is open or shorted, Fuel injector 3 circuit poor electrical connection, Ignition coil 3 harness is open or shorted, Ignition coil 3 circuit poor electrical connection, Insufficient cylinder 3 compression, Incorrect fuel pressure, Intake air leak...The P0303 code means that the cylinder 3 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 3. If the problem persist more tests needs to be done to diagnose problem.
Search Nissan Altima Questions
Nissan Altima Experts