1999 Chevy Silverado Fault Codes P0327, P0171, and P0174: Diagnosis and Solutions

I recommend visiting an AutoZone or similar auto parts store to get a diagnostic tool. They can help identify which component is associated with each code, and often have reference guides like Chilton or Haynes manuals available for specific models such as the 1999 Chevy Silverado.

After checking both Chilton and Haynes manuals for my 1999 Silverado, I couldn't find a direct listing for P0327 or related codes. This suggests the issue may require more advanced diagnostics or specific troubleshooting steps.

Calling any auto parts store directly is another option—ask if they carry replacement sensors or components that match the fault codes, and where those parts are typically installed in a 1999 Chevy Silverado.

I've noticed an unusual noise on my truck, which appears to originate from the driver's side of the cab. It sounds similar to exhaust spattering but remains consistent whether at idle or highway speeds (70 mph). I'm struggling to pinpoint its source—could it be related to a faulty exhaust component or drivetrain? Any suggestions for further diagnosis?

I’d need to hear the noise firsthand to make an accurate assessment. A visual or audio reference would help determine if it’s mechanical, thermal, or otherwise.

The sound isn’t rattling—it's more of a steady hum. I’m wondering if the torque converter might be the source. However, due to safety and accessibility concerns, I don’t have the ability to record it directly.

I once had a similar noise on my 1998 Grand Am, which turned out to be a failing catalytic converter. If the torque converter is suspected in your case, replacing it could resolve the issue—though this should only be done after proper diagnosis.

I'm still uncertain about the exact origin of the noise. It may require a more detailed inspection or specialized equipment to identify.

A long rubber hose with a metal rod at one end can act as a makeshift stethoscope. Place it against suspected areas, especially hot spots, and listen through the other end into your ear. If possible, use a mechanic’s stethoscope for better accuracy.

I drove approximately 500 miles over the weekend with the check engine light on during a trip to Hill Country. After clearing the codes at my cousin's shop yesterday, the light came back on after just 10 minutes of driving. I then took it to a state inspection and passed. Was this luck—or is there something about these fault codes that allows temporary clearance?

It's not uncommon for drivers to experience intermittent clearances due to transient conditions—such as temperature, fuel quality, or sensor calibration. While it may seem like luck, it could reflect a non-critical issue that resolves under certain operating conditions.

I have a question about my 1999 Chevy Silverado: if I were to temporarily block the exhaust pipe while the engine is running, what would happen? Would it cause immediate stalling or damage?

Banana in the tailpipe! Axle Foley! (A humorous reference—blocking the exhaust will likely cause severe engine performance issues and potential damage.)

Here’s another issue: when I start my truck, it runs smoothly at idle. However, as soon as I press the accelerator, it begins to shake and behaves like it's running on poor fuel. Any ideas about what could be causing this? Could it be a vacuum leak or faulty fuel injectors?

Let’s keep this thread focused—posting multiple times in long, unstructured threads makes it hard to follow and reduces the value for other users. A concise, well-organized discussion would be more helpful.

This thread is now locked due to repeated off-topic posts and lack of focused technical discussion. Please refer to dedicated forums or resources such as OBD-II code databases for accurate troubleshooting.

For reference, there's a detailed article on P0327 available here: http://www.obd-codes.com/p0327