p1300 code help! (1 Viewer)

[303perspective]

Out of nowhere about a week ago, my '00 LC started misfiring and running extremely rough... went to check the CEL codes and was getting
P0300- Random multiple misfire
P0301- Cyl 1 Misfire
P0303- Cyl 3 Misfire
P1300- Igniter Circuit no. 1 Malfunction
I dont know what to do to fix it and was hoping for some advice from the elders. I replaced all the sparkplugs and coil packs about 2,000 miles ago and it was running amazing till the codes. I replaced the two coilpacks on the misfiring cylinders and it ran great for all of 2 days, and now runs somehow worse and is still throwing the codes. I read up on this form:
P1300 code - https://forum.ih8mud.com/threads/p1300-code.715038/#:~:text=Apparently%20P1300%20means%20Ignitor%20Circuit%20malfunction ; and all I found was that it could be the coil, spark plug, or wiring. Not much I found about the p1300 code on here. With just replacing the coils, should I try a new new set since I have a free replacement warranty, or should I dive into sparks or wiring? Im in a college dorm so have limited tools and I don't wanna pay 250+ for a hopefully simple diagnosis.
Thanks for any help!
2000 LC with duralast coilpacks and ngk sparks.

Update: switched the coil packs from 1/3 to 5/7 and now im getting a cylinder 4 misfire, which I didn’t even touch. What the hell

 

[kevgentile]

Are you getting the misfire on the same 2 cylinders after the coil swap?

 

[2001LC]

Where did you get the plugs and coils, which bran (manufacture) and how much did you pay. I ask because, the typically Chinses made bootlegs, last about 2k to 20K miles. The coils are usually from ebay, for $50 ea. or under.

 

[303perspective]

Are you getting the misfire on the same 2 cylinders after the coil swap?

Are you getting the misfire on the same 2 cylinders after the coil swap?

Yes, with an added cyl 4 all the sudden today

 

[kevgentile]

Yes, with an added cyl 4 all the sudden today

You can move around the coils to see if the misfire moves with them. Swap the plugs too if no change moving the coils.
If the problem persists on those cylinders you're going to have to start checking the injector circuit.

If you're not comfortable with a wiring diagram and a multimeter you'll find yourself just throwing parts at it.

 

[kevgentile]

Also, as @2001LC mentioned, cheap parts are cheap parts and often result in creating more problems. Especially over the last 3 years.
QC went in the toilet and there has been a major downfall in part quality and quality part availability. At our shop we have even seen a rash of name brand parts take a dump out of the box. But at least when buying quality parts you'll often get goo warranties with them.

 

[kevgentile]

I overlooked your mentioning of the igniter circuit fault. There are 2 ignition circuit relays, one for each bank, that feed off a high amp power feed.
Since you don't have a #2 misfire I'd be inclined to focus on the other areas mentioned, but it's a possibility since #4 kicked in now too.

 

[303perspective]

Also, as @2001LC mentioned, cheap parts are cheap parts and often result in creating more problems. Especially over the last 3 years.
QC went in the toilet and there has been a major downfall in part quality and quality part availability. At our shop we have even seen a rash of name brand parts take a dump out of the box. But at least when buying quality parts you'll often get goo warranties with them.

yeah id believe you on that for sure! I got them from autozone, and I know NGK is a pretty repulable brand and Duralast isnt anywhere as good as Denso ones but autozone has a lifertime free replacement on them, so ill take it i guess. Sucks to see where we stand today as a society lol.

 

[2001LC]

yeah id believe you on that for sure! I got them from autozone, and I know NGK is a pretty repulable brand and Duralast isnt anywhere as good as Denso ones but autozone has a lifertime free replacement on them, so ill take it i guess. Sucks to see where we stand today as a society lol.

I once bought a lot from Advance Auto, which owns World Pac. Local Toyota Dealership buy from them too.
I stopped buying for them. As I was get 25% bad spark plugs, than 50% bad, then I hit 100% in a set bad. They were all Denso (on the box) spark plugs.
How this junk is getting into parts store, I can only guess.

Last 4 years or so. I've been buying direct from denso wholesaler/distributor. 100% in over 80 spark plugs, perfect. Not one bad one.

I've also had issue with authentic name brands, like Duralast, etc..

If you like to come by. I'll hook you up to tech stream. See if you're getting any misfire. I've quality Dense TT spark plugs, NGK. Also Denso and Toyota Denso, coils. I've also good use Toyota factory coils. All on hand, all bought from Toyota, Distributors or pulled from working. We can pick one cylinder missing fire, and swap in plug and or coil. PM if you like!