Need help with my 2006 Pontiac g5 pursuit!!

[sc123]

It has 3 codes: P0301 (Cylinder 1 Misfire), P0446 (Evaporative Emission Vent System Performance), and P1174 (Fuel Trim Cylinder Balance). I’ve changed the coil spark plugs, replaced #1 coil. I’ve done 2 sea foam treatments. Idk what it could be. I don’t smell gas so I don’t think it’s a gas leak. It has a rough idle when it’s in neutral, like a sputtering sound almost (not backfiring), and it has a slight hesitation fuel injectors? I have no idea. The photo I attached under the “misfiring engine” title explains perfectly what my car is experiencing.

 

[melsg5]

P0446 is not causing your problem.
Start with P0301

OBD-II Trouble Code: P0301 Cylinder 1 One Misfire Detected

 

[sc123]

-Faulty spark plug or wire (changed all 4 coil spark plugs, which resulted in more power but still have hesitation)
-Faulty coil (pack) Changed #1 coil
-Faulty oxygen sensor(s) (how do I check for this?)
-Faulty fuel injector (how do I tell if a fuel injector is damaged, I know where the fuel rail is located, but visually, how can I diagnose this possible problem?)
-Burned exhaust valve (How do I diagnose this)
-Running out of fuel (What does this mean?, is it referring to poor fuel mileage? If so, I don’t have this symptom).
-Poor compression (How would I do a test for this?)
Thx for your time!

 

[melsg5]

The answers to your questions are easily found just by looking them up. Testing O2 sensors and compression tests are all out there.
Have you done a fuel pressure test?

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[sc123]

No I have not. I will do some research thanks again for your time

 

[sc123]

So I did a compression test all the coils are good so that rules that out. Changed my gas cap the seal was bad. Any idea what it could be now? Checked all the vacuum hoses etc. The only problem I noticed was a very dirty air filter could that be cause for the code?

 

[melsg5]

The air filter could cause the P1174.
What were the compressor readings?

 

[sc123]

Coil #1 (newest one I’ve changed): 130, and the other 3 coils were 120.

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[melsg5]

Those cylinder readings are somewhat low.
Did you follow a procedure similar to this one?

Part 1 -How To Test Engine Compression (2006-2012 2.4L Ecotec)

Symptoms of Low or No Engine Compression. P0300, P0301, P0302, P0303, P0304. Finding the Dead Cylinders.

troubleshootmyvehicle.com

Did you replace the air filter?

 

[sc123]

Yes I followed that exact procedure with the compression tester. I have not replaced it yet but I am going to replace the air filter under the hood as well as the cabin filter. Do you think a fuel pump could cause a misfire ?

 

[melsg5]

Not on 1 cylinder
I recommended the fuel pressure test for the P1174 but that was before you said anything about the air filter.
It is a stock air filter?

 

[sc123]

I’m not exactly sure, I’m guessing so. There was 2 owners before me, and I’ve had this car for 3 years I’m guessing they didn’t do regular maintenance. But I found some filters for my exact make/model, so I’m sure that will make a difference if I change both filters hey?

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[melsg5]

The engine filter may effect the codes.

 

[sc123]

Ok I’ll be sure to do that. I really appreciate your time and getting back to me. You’ve help me sooo much! So thank you it means a lot!!!

 

[sc123]

Hi so my cars engine light is blinking it has done this twice... I did some research and that means that it is a serious problem and I shouldn’t drive it! It also says that could mean catalytic converter damage is that true ? I ordered new parts: 4 fuel injectors, fuel pump, cabin air filter & vent filter.

 

[melsg5]

If you have an overly rich mixture due to a clogged air filter or other causes you can burn out the cat.

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[sc123]

Do you think it’s already burned out ? Or do you think it’s still safe because it’s only blinked twice so far

 

[melsg5]

I would think so since you have no code related to the cat

 

[sc123]

Hi I changed both air filters, but the housing for the air filter a clip broke on it so it slightly doesn’t close properly... it’s the tiniest gap. Would this mess up my air to my engine?

 

[melsg5]

If it sucks in unfiltered air, it's not great.