Toyota Repair Problems? Ask a Mechanic for Answers ASAP
Hello and thank you for using just answer.
Verify for me here- this is a 2002 4 cylinder correct? Are all these codes currently stored?
You have 2 issues here.
First let's seperate the codes.
P0446 is most likely why the light has been on for a while, this is a EVAP system leak, not a big deal right now or anything to be alarmed about, this is most likley just a bad fuel cap or loose line.
What you need to focus on is the p300 codes and p1300.
P1300 is an igniter circuit code. You are incorrect on your coil information.
Each cyliner has it's own coil pack bolted above the spoark plug, this contains the coil and igniter for each of the independant cylinders. Most likely you have 1 bad ignition coil here, to properly diagnose this you need a scn tool to read the data list to "see" what cylinder is misfiring. Do NOT waste your $$$ on a coil from anywhere other then the dealer, trust me on this one. Get 1 new coil and move it around if you don't have a scan tool to better trace this. I am about to drive home here but will be back online shortly if you need more input on this.
Yes this can be a little confusing, each coil pack has 4 wires, a power, a ground, a igt and an igf signal, the power and ground energize the coil, igt and igf are the computer signals to fire and to tell the computer that the coil did fire. When igf does not send signal back it sets the p1300 code, you need an osciloscope to check these 2 signals.
Also be aware of a few more things here:
1- the catalytic converter is VERY sensitive on this car and very expensive, plan on a $800 part if you keep running this engine with a misfire
2- spark plugs- you need to be sure you used IRIDIUM spark plugs, required by this system
3- still needing a scan tool here, unplugging a coil is not the proper way to check for a misfire, you need to read the misfire data list to determine this.
I would take that new coil and move it around to each of the 4 cylinders to see if this clears it up if you have no scan tool access or install a spark tester to "see" spark.
I have to be honest, yeah I'm laughing a little right now, yes autolite and Bosch are both horrible plugs for this motor, sounds like you got taken advantage of at autozone last night. I highly recommend only a NGK or a Denso spark plug in this car. However the spark plug will not cause a constant/heavy misfire as you have right now or the p1300 code.
Before you spend $100 on a diag fee have you checked to see what scan tools are available at auto zone? All you need is a scan tool that can read codes and data lists.....many parts stores also RENT scanners or high quality. I would like to guide you through this here to save you some $$$ but certain things will require some scan tool tests. My fear here is you start throwing parts at the car and not resolve anything or possibly damage a $800 converter.
We need to see a datalist for misfires at this point.
As long as you have compression then you will find that a coil or a fuel injector is the issue here.
Logging out for dinner, I'll be back shortly if you need me.
Yes disconnecting the battery will clear the memory in the ECM and reset the light, disconnect the battery for several minutes.
NO DO NOT DRIVE THE CAR! I guarantee a $800 catalytic converter failure and major issues if you do so. Stop driving this car. As I stated before my intention is to help you here and try to save you $$$$, if you drive this car you defeat the purpose and intentionally cause additional damage.