Ok well I have a 2001 Eclipse spyder gs with a code of po300 I've replaced all the spark plugs & wires as well as the fuel pressure regulator and ecm and mass air flow censor and checked the mounts
6 Answers
Is it actually missing or just the check engine light is on?
http://www.obd-codes.com/p0300
P0300 is a random misfire. Meaning all cylinders are misfiring, Its something in common. 1. vacuum leak can cause this. you may have a high idle with a vac leak. 2. not sure on ignition setup on those cars, but if a single ignition coil is used this can be suspect as well as distributor cap and rotor. ( ignition misfire will present itself more so under engine load.) 3. A weak fuel pump, not common but i have seen it. (check fuel pressure should be around 50-60 psi) a clogged fuel filter is possible, but it would choke and stall while driving. check these things first. hope it helps. Pete
If it's just the cel then I would try unhooking battery for at least ten minutes. This will clear the code. Drive car and see if cel comes back on.
If it has a miss you can feel look at your coils. They tend to leave a carbon trace mark where they are arcing out. Also try some good fuel treatment. I use sea foam or CTC. Bad gas can cause a 300 code.
mine's had the same code p0300 turned out to be 2 bad fuel injector's total cost $935