How to clear P0302 and P0303 codes, and replacement of fuel injectors?

2009 HONDA ACCORD
161,098 MILES • 2.4L • 4 CYL • 2WD • AUTOMATIC
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XJSHEN
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P0302 and P0303 codes appeared, even after replacing spark plugs and coils. I suspected fuel injectors problem, and tested their resistances with multi meter, but four injectors showed all similar resistance around 11.04 Ohm. And I found the 3 injectors 3 and 2 were loose in their cells that I thought may be O=rings damaged?

I want to remove injectors, but I could not find answers to my question on YouTube site.

How to replace fuel injectors on Honda accord 2009?

Thanks for your comments and helps!
May 19, 2025 at 3:48 PM
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STRAILER
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Yes, testing the resistance does not always work, it is more about the injector nozzle. I would remove the injectors as you are thinking and use this guide as a test:

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Here is how to remove the fuel injectors in the images below. Let us know what you find.


May 20, 2025 at 9:06 AM
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XJSHEN
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Thanks a lot Ken!
I did the Fuel Injector Winding Test, and the results on the four injectors resistance were all near 11.04 ohm.
I will do the Injector Circuit Power Test tomorrow.
and I need a detailed protocol how to remove injectors. I am wondering why there were no protocols. may be too complicated?
If you could send me a copy of the repair manual on this topic, please.
I replaced new spark plugs and coils on #2 and #3 problematic cylinders. And I tried to start up engine, but I could not start the engine. there was no crank voice. if the starter was gone? I charged battery from 11.47 V 78% 12.6 V to 99%.
I attached images of light on dashboard. May you instruct me about possible cause of the problem?

Thanks
May 20, 2025 at 5:32 PM
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STRAILER
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I don't see the images. can you please reload them?
May 22, 2025 at 9:55 AM
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XJSHEN
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Today I did an injector circuit power test using the voltmeter negative side connected to the negative side of the battery. key on at III position without start engine, positive end probe both sides of injector wiring connector. the voltage showed all zero on all four injector wires, indicating circuit was disconnected. so, I need to check the wires and connectors.
I tested the engine starter, with voltmeter set 12V, connected on both battery ends, and checked voltage changes when key on starting position. There was voltage decrease from 12.7V to 10 v, indicating starter may be OK. But no crack sound when turned key to the start position.
What I did before just charged battery with charger and disconnected injector connector. I do not know what happened. If there may be fuse broken case?
Thanks for your instruction and helps!
May 22, 2025 at 6:20 PM
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XJSHEN
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I tried uploading images for several times with TIFF, PDF, PPT format but all were failed with filetype not allowed.
May 22, 2025 at 6:36 PM
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STRAILER
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Can you try jpeg or gif? Also, it sounds like you have two problems, one the injectors are not getting power? and the starter does not work, can you confirm?
May 23, 2025 at 11:28 AM
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XJSHEN
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The images were lights on dashboard when key on III position without start. It’s normal. Yes, there are two problems now: first, I don’t know if injector 2 and 3 bad that caused p0112, p0113?
Second, now a new problem is the engine couldn’t startup with all injector wires losing power. When turn start key, no crank sound, but it changed battery power from 12.7v to 10v, indicating starter was not dead?
If specific fuse was broken? Or wire was disconnected?
I was going to check vacuum leak and fuel line pressures, but engine couldn’t startup now.
I need diagram from injector line to battery and battery to solenoid and starter diagram.

The cause of new problems probably the same on power lack on starter and injectors.
Thanks for your help!
May 23, 2025 at 11:14 PM
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STRAILER
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Sure here are the wiring diagrams for the PCM power and the starter system. Let me know what you find. Try uploading a video?
May 25, 2025 at 11:03 AM
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XJSHEN
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Hi Ken!
I couldn’t identify the part and its location as well their circuit. If you could kindly provide detail detection video or text documentation?
Thanks a lot for your help!
Jun 21, 2025 at 6:55 AM
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Sorry, we only handle one problem per thread, please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Let me know what happens with this problem. Cheers, Ken
Jun 22, 2025 at 12:20 PM
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XJSHEN
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Hi Ken,
Thanks a lot for your many precious instructions and help!
I replaced the spark plugs, coil packs, and fuel injectors, detected voltages, voltage down, resistance, and checked fuses, and all plug wires. Now no code, and with cycle relearning drive activated five inactivated functions on OBD-II auto scanner. And got through inspection and renewed registration.
The new problem now is that fuel trims lean, ST FTRM1 (%) was -0.85(%), and LT FTRM1 (%) WAS -14.0(%), and after cleared codes, there was no freeze frame stored, no freeze frame events detected.
With lean fuel trim data, car was powerless than before, and hard to increase speed from start to 40 mph, after then, it was no problem increase from 40 mph to 70 mph on the highway.

How to fix the problems practically by myself?
Aug 21, 2025 at 9:48 AM
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STRAILER
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Sorry, we only handle one problem per thread, please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new
Aug 21, 2025 at 10:31 AM