The P1154 code on your 2020 Chevrolet Tahoe indicates that the fuel trim system on bank 2 is running leaner than expected. This GM-specific code affects your Tahoe's 5.3L or 6.2L V8 engine, signaling that the PCM is compensating for a lean condition on the passenger side cylinder bank by adding fuel beyond normal parameters.
Understanding P1154 on Tahoe
Bank 2 refers to the cylinder bank opposite cylinder #1, which on GM V8 engines is the passenger side. When P1154 sets, the PCM has detected consistently positive fuel trim corrections on bank 2, meaning more fuel is being added to achieve proper air-fuel ratios. This compensation indicates unmetered air is entering bank 2 or fuel delivery is insufficient.
Common Symptoms
- Check engine light illuminated
- Rough idle, especially when cold
- Hesitation during acceleration
- Misfires on bank 2 cylinders
- Decreased fuel economy
- Possible lean misfire codes (P0300-P0308)
Primary Causes
- Vacuum leak on bank 2 intake runners
- Cracked or loose intake manifold gasket
- Faulty bank 2 oxygen sensor reading rich (causing lean compensation)
- Clogged fuel injector on bank 2
- Low fuel pressure affecting bank 2 more than bank 1
- EGR valve stuck open
- PCV system issues
Diagnostic Procedure for 2020 Tahoe
Begin by comparing bank 1 and bank 2 fuel trim values. Significantly higher positive trims on bank 2 indicate an isolated issue. Perform a thorough smoke test focusing on bank 2 intake runners and the intake manifold gasket area. Test each fuel injector on bank 2 using a noid light and resistance testing. Swap upstream O2 sensors between banks to determine if the sensor is causing incorrect readings. Check EGR valve operation.
Repair Solutions
Repair vacuum leaks identified through smoke testing with appropriate gaskets or components. Replace any O2 sensors confirmed faulty through swap testing. Clean or replace clogged fuel injectors. Address EGR valve issues if stuck open. If intake manifold gasket is leaking, replace the complete gasket set. Clear codes and verify fuel trims normalize during extended test drive.