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2004 Chevrolet 2500 V8 Gas Truck with P0174 and P0307 Codes: Diagnosis and Solutions

Model: chev truck Fault Code: P0174 Posted: 2013-02-12 22:55

Hello everyone, I'm trying to avoid unnecessary part replacements before investing in repairs. My vehicle is a 2004 Chevrolet 2500 V8 gasoline truck, currently showing diagnostic trouble codes P0174 and P0307. I've already performed several maintenance steps: cleaned the Mass Air Flow (MAF) sensor, replaced the air filter, and recently installed new spark plugs and wires (about 4-6 months ago). I'm using an AutoLink AL419 device to retrieve and monitor live data. While driving, I notice that during live readings, the 'Short Term Fuel Trim Bank 1 - Sensor 2' value displays as 'N/A', while all other sensor values are available. My question is: could this missing reading be contributing to or triggering the P0174 code? Any insights into how this might affect fuel trim behavior or whether it points to a deeper issue would be greatly appreciated. Thanks, Tim

Related fault codes
P0174
Comments (4)
Anonymous 2013-02-13 09:25

Could you clarify which V8 engine model you're referring to? Start with an injector cleaner like Techron or SeaFoam. Were the spark plugs and wires replaced by AC Delco? P0307 specifically points to cylinder #7 — remove the plug and check for wet, dry, black, or tan deposits. Can you test the injector using a noid light or digital multimeter (DVOM) to verify continuity? Also, when you can access Short Term Fuel Trim (STFT) or Long Term Fuel Trim (LTFT), what values are you seeing?

Anonymous 2013-02-14 01:40

It's a 6.0L V8 gasoline engine. From my live data readings, I get the following: - SHRTFT1(%) - from 8.9% to 5.5% - LONGFT1(%) - from 9.3% to 11.7% - SHRTFT2(%) - from 1.6% to 14.8% - LONGFT2(%) - from 11.7% to 25% Are these values accurate and consistent with what you're seeing? Thanks, Tim

Anonymous 2013-02-14 10:15

No specific numbers were needed — I see that the Long Term Fuel Trim (LTFT) for Bank 2 is showing a lean correction. This suggests either a vacuum leak or a faulty fuel injector. I recommend starting with a vacuum leak check using the spray test, especially around cylinder 7 on the intake manifold. As a diagnostic step, consider swapping Injector #7 with another cylinder and monitoring whether the misfire follows to the new location. However, checking the spark plug condition and performing an ohm test on the injector will provide more immediate clarity.

Anonymous 2013-02-14 20:49

Thanks for the helpful tips, Kev! I'll head out tomorrow to investigate further. I've already checked for vacuum leaks, but now I'm realizing I may not have thoroughly inspected the area around cylinder 7. I’ll take a look at the injector while I’m there. Tim