Error Codes P0332 and P0171 & 0174

04-10-2013, 09:26 AM
Good Day All:

I have a GMC Yukon XL 2002 5.3 V8
The check engine light is on and the codes are P0332 Knock Sensor Circuit Low Frequency Bank 2
The other codes are P0171 and P0174 both are referring to fuel trim system lean bank 1 and 2.
First question: Could these error codes be related?
Second P0332 knock sensor: to remove the air intake manifold the gasket should/will also need to be replaced correct.
Third Question Fuel Trim System Lean: What does that mean and where does that direct me for repairs.

Thank you


04-10-2013, 09:43 AM
Yes, they could all be related. the 171 and 174 both set tells me you have a vacuum leak. The 5.3 was bad about vacuum leaks at the intake gaskets. If you had a scanner that monitored fuel trim, you could vent some propane at the base of the intake and watch the fuel trim change. I would change the gaskets and replace the knock sensor when the intake was out.

05-23-2013, 09:16 PM
error code table:

08-28-2014, 12:57 PM
Most likely intake gasket leak & if you ever washed engine or driven through deep deep standing water, more than likely knock sensor got wet. Have intake gasket replace and be sure to replace both knock sensors when having intake gasket replaced.

ky wonder
03-07-2020, 03:19 PM
Before you do that, replace the evap purge valve just behind the alternator, this valve can stick in the open or close position, causing the clean codes as well, good news is you can by one online for 20 bucks. And put it on yourself if you have any aptitude at all, simple unplug, and plug back
YouTube is your friend

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