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2003 Chevrolet Impala LS 3.8L MIL Lamp on
Posted to GM Driveability on 3/23/2015 24 Replies

Got this impala that has a p0420 and p0128 for thermostat and cat efficiency. I went ahead and slapped a thermostat in it because it was very quick and easy to do. That brought the temperature back up to specs. My question is the p0420. I didnt look at the o2s...

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  Related Documents & Media  2003 Chevrolet Impala LS

 
Message Closed w/FIX

car Vehicle Data

2003 Chevrolet Impala LS

VIN 2G1WH55K13
Engine3.8 L / 6 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsMIL Lamp On

Trouble Codes

P0128Cooling System Malfunction
P0420Catalyst Efficiency Below Threshold (Bank 1)
Message Closed w/FIX

car Vehicle Data

2003 Chevrolet Impala LS

VIN 2G1WH55K13
Engine3.8 L / 6 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsMIL Lamp On

Trouble Codes

P0128Cooling System Malfunction
P0420Catalyst Efficiency Below Threshold (Bank 1)