P0302 and other weird stuff happening help! - Toyota Yaris Forums

phyrefighterjay · 09-08-2021, 02:12 PM

Hey thanks to you all for helping me with this situation. This yaris has 300k miles on it and this is my FIRST check engine light! Here is the time line of what ive done to it. And what is happening
1. Replaced Spark plugs 15k miles ago
2. Removed and cleaned airflow sensor with airflow sensor cleaner spray.
Everything was normal...till now
3. I noticed a Minor chugging only when cold. Seemed to smooth out just fine at any rpm above 1000
4. The siren for my lights being on has been sporadic… Leading me to running the battery dead at least 2 to 3 times because I left my lights on…
5. I refilled the battery with distilled water and trickle charged it so the battery was good as verified by an apparatus at the parts store
6. While accelerating on the freeway… Check engine light came on… Motor was running just fine. I pulled off and got an analysis at an auto parts store and got code P0302… And secondary code P0304
7. I bought a coil for the second cylinder and nothing changed… The engine ran just fine but the code remained and the engine light stayed on.
I bought a coil for the second cylinder and nothing changed… The engine ran just fine but the code remained and the engine light stayed on.
8. The engine ran just fine all the way home from Orlando… But this morning I woke up to the same CEL and now a battery light. I drove it to the auto parts store. I replace the battery and replace the alternator. The battery light went away but the CEL light remained. Now the engine doesn’t even idle very well.
9. I checked all of the injectors… They all came back with 14.2 ohms of resistance.
So...I think the coils are good but I will check them with a multimeter. I think the spark plugs are good they were changed only about 15,000 miles ago. To my knowledge I think the fuel injectors are good. But the car has 300,000 miles on it so it could be anything. I’ll let you guys take it from here. Fuel filter?

09-08-2021, 02:12 PM	#1
phyrefighterjay Drives: 07 yaris sedan Join Date: Apr 2009 Location: Bailey Co Posts: 31	P0302 and other weird stuff happening help! Hey thanks to you all for helping me with this situation. This yaris has 300k miles on it and this is my FIRST check engine light! Here is the time line of what ive done to it. And what is happening 1. Replaced Spark plugs 15k miles ago 2. Removed and cleaned airflow sensor with airflow sensor cleaner spray. Everything was normal...till now 3. I noticed a Minor chugging only when cold. Seemed to smooth out just fine at any rpm above 1000 4. The siren for my lights being on has been sporadic… Leading me to running the battery dead at least 2 to 3 times because I left my lights on… 5. I refilled the battery with distilled water and trickle charged it so the battery was good as verified by an apparatus at the parts store 6. While accelerating on the freeway… Check engine light came on… Motor was running just fine. I pulled off and got an analysis at an auto parts store and got code P0302… And secondary code P0304 7. I bought a coil for the second cylinder and nothing changed… The engine ran just fine but the code remained and the engine light stayed on. I bought a coil for the second cylinder and nothing changed… The engine ran just fine but the code remained and the engine light stayed on. 8. The engine ran just fine all the way home from Orlando… But this morning I woke up to the same CEL and now a battery light. I drove it to the auto parts store. I replace the battery and replace the alternator. The battery light went away but the CEL light remained. Now the engine doesn’t even idle very well. 9. I checked all of the injectors… They all came back with 14.2 ohms of resistance. So...I think the coils are good but I will check them with a multimeter. I think the spark plugs are good they were changed only about 15,000 miles ago. To my knowledge I think the fuel injectors are good. But the car has 300,000 miles on it so it could be anything. I’ll let you guys take it from here. Fuel filter?