Need help! with DTC's P0300, P0301, P0303, P0305!!
02-18-22, 03:53 AM
#1
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Need help! with DTC's P0300, P0301, P0303, P0305!!
so I had some pretty decent seepage coming from the valve cover gasket closest to the radiator on my 97 ES300. I figured while I was under the hood I would replace the spark plugs since they hadn't been done in a while. I got the NGK laser platinums which I have always put in this vehicle and the change went as routine as they go. however upon initial startup after the plugs and valve cover replacement. y I got a check engine light and the code was p0302 cylinder #2 misfire. I found that to be strange considering I did not have an issue prior to replacing the plugs however didn't think much of it ran to O'Reilly grabbed a coil through it in and all seem to be well on test drive number 2 which was only about 10 or 15 minutes long. well the next morning as I'm heading to work I noticed the vehicle is idling very rough and has very low power in low RPM. and by the time I got to work my check engine light had come on and be gone flashing and the codes read p0300 random multiple misfires ,and p0301, p0303, p0305 cylinder misfires in cylinders and 1,3, and 5. as if these codes being thrown all at once weren't enough to perplex me the car runs pretty good as long as you're accelerating but at idle or low RPM it's rough and sluggish.. I have verified that all fuses are in good condition plug wires going from the front coils to the back spark plugs are in the proper order. I haven't placed all three coils with known good Toyota OEM coils. I've checked all wire connectors and wiring to the coils and have replaced the igniter yet still have the same codes and the same running issues. anyone have any idea it's starting to drive me crazy
02-18-22, 07:58 AM
#4
Pole Position
Hello,
When was the last time the Spark Plug Wires were replaced?
Where did you get your spark plugs?
Cylinders 1,3 and 5 all belong to the Bank 1, on the back of an engine, they are getting their power from the High Voltage Wires. From the symptoms, it looks like your wires went bad, probably the isolation is not as strong as it used to be, so they can't hold as much voltage anymore. If that's the case, try accelerating slowly in Neutral and then flooring it, accelerating slowly would go smoothly, flooring it would cause the car to dip and shudder for a moment. Inspect the wires for any cracks in the isolation, corrosion, any kinds of degradation, you should also check their resistance as well; if they are still original, you should just replace them. If that won't help, you can get yourself a spark tester like this one, which allows you to test the strength of the spark.
Hope this helps and best of luck!
When was the last time the Spark Plug Wires were replaced?
Where did you get your spark plugs?
Cylinders 1,3 and 5 all belong to the Bank 1, on the back of an engine, they are getting their power from the High Voltage Wires. From the symptoms, it looks like your wires went bad, probably the isolation is not as strong as it used to be, so they can't hold as much voltage anymore. If that's the case, try accelerating slowly in Neutral and then flooring it, accelerating slowly would go smoothly, flooring it would cause the car to dip and shudder for a moment. Inspect the wires for any cracks in the isolation, corrosion, any kinds of degradation, you should also check their resistance as well; if they are still original, you should just replace them. If that won't help, you can get yourself a spark tester like this one, which allows you to test the strength of the spark.
Hope this helps and best of luck!
02-18-22, 01:50 PM
#5
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Hello,
When was the last time the Spark Plug Wires were replaced?
Where did you get your spark plugs?
Cylinders 1,3 and 5 all belong to the Bank 1, on the back of an engine, they are getting their power from the High Voltage Wires. From the symptoms, it looks like your wires went bad, probably the isolation is not as strong as it used to be, so they can't hold as much voltage anymore. If that's the case, try accelerating slowly in Neutral and then flooring it, accelerating slowly would go smoothly, flooring it would cause the car to dip and shudder for a moment. Inspect the wires for any cracks in the isolation, corrosion, any kinds of degradation, you should also check their resistance as well; if they are still original, you should just replace them. If that won't help, you can get yourself a spark tester like this one, which allows you to test the strength of the spark.
Hope this helps and best of luck!
When was the last time the Spark Plug Wires were replaced?
Where did you get your spark plugs?
Cylinders 1,3 and 5 all belong to the Bank 1, on the back of an engine, they are getting their power from the High Voltage Wires. From the symptoms, it looks like your wires went bad, probably the isolation is not as strong as it used to be, so they can't hold as much voltage anymore. If that's the case, try accelerating slowly in Neutral and then flooring it, accelerating slowly would go smoothly, flooring it would cause the car to dip and shudder for a moment. Inspect the wires for any cracks in the isolation, corrosion, any kinds of degradation, you should also check their resistance as well; if they are still original, you should just replace them. If that won't help, you can get yourself a spark tester like this one, which allows you to test the strength of the spark.
Hope this helps and best of luck!
at it and no difference...
02-18-22, 03:10 PM
#6
Pole Position
Did you check the old set of wires?
What brand coil and wires did you get?
Get a spark tester and see how strong of a spark can you get, both from coil itself and the wire, that will tell you whether the ignition system is fine and it is time to look elsewhere. You wrote that you replaced Cylinder 2 coil, did it make any difference in regards to P0305? Try putting the old OEM coil in to see what difference will it make.
Hope this helps and best of luck!
What brand coil and wires did you get?
Get a spark tester and see how strong of a spark can you get, both from coil itself and the wire, that will tell you whether the ignition system is fine and it is time to look elsewhere. You wrote that you replaced Cylinder 2 coil, did it make any difference in regards to P0305? Try putting the old OEM coil in to see what difference will it make.
Hope this helps and best of luck!
02-26-22, 01:09 AM
#7
Driver School Candidate
so I had some pretty decent seepage coming from the valve cover gasket closest to the radiator on my 97 ES300. I figured while I was under the hood I would replace the spark plugs since they hadn't been done in a while. I got the NGK laser platinums which I have always put in this vehicle and the change went as routine as they go. however upon initial startup after the plugs and valve cover replacement. y I got a check engine light and the code was p0302 cylinder #2 misfire. I found that to be strange considering I did not have an issue prior to replacing the plugs however didn't think much of it ran to O'Reilly grabbed a coil through it in and all seem to be well on test drive number 2 which was only about 10 or 15 minutes long. well the next morning as I'm heading to work I noticed the vehicle is idling very rough and has very low power in low RPM. and by the time I got to work my check engine light had come on and be gone flashing and the codes read p0300 random multiple misfires ,and p0301, p0303, p0305 cylinder misfires in cylinders and 1,3, and 5. as if these codes being thrown all at once weren't enough to perplex me the car runs pretty good as long as you're accelerating but at idle or low RPM it's rough and sluggish.. I have verified that all fuses are in good condition plug wires going from the front coils to the back spark plugs are in the proper order. I haven't placed all three coils with known good Toyota OEM coils. I've checked all wire connectors and wiring to the coils and have replaced the igniter yet still have the same codes and the same running issues. anyone have any idea it's starting to drive me crazy
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