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Dan, Technician
Category: Chevy
Satisfied Customers: 24577
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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What should i do for codes P0172 and P0300 for 2003 chevy caviler

Customer Question

what should i do for codes P0172 and P0300 for 2003 chevy caviler
Submitted: 6 years ago.
Category: Chevy
Expert:  Dan replied 6 years ago.

Welcome to JustAnswer, my name is Dan and I'm here to help get your problem resolved. Ask follow up questions, thanks.


Does check engine light ever flash? Does it run rough?

Customer: replied 6 years ago.
doesn't flash is just on and yes its running rough
Expert:  Dan replied 6 years ago.

Pull the vacuum line off the fuel pressure regulator if fuel comes out then its leaking and will need to be replaced. You can disconnect front oxygen sensor, disconnect battery for 10 minutes then see if it runs better if so replace oxygen sensor. You can also clean out throttle body and mass airflow sensor with approved cleaner. Disconnect mass airflow sensor if it runs better replace it, if cleaning doesnt help. You could also make sure injectors ane purge valve are not leaking. Let me know if you have questions, thanks.


P0172 Fuel System Rich (Bank 1)

Possible CausesSetting Conditions
  • Base engine "mechanical" fault affecting one or more cylinders
  • EVAP system component has failed or canister fuel saturated
  • Fuel control sensor is out of calibration (i.e., ECT, IAT or MAP)
  • Fuel system supplying too much fuel at idle speed or at cruise
  • Fuel injector(s) is leaking or stuck partially open (one or more)
  • HO2S element is contaminated by the fuel, or silicon contaminated
DTC P0105, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0141, P0201-P0204, P0300, P0301-P0304, P0326, P0336, P0340, P0341, P0442, P0446, P0452, P0453, P0455, P0481, P0496, P0502, P0503, P0506, P0601, P0602, P0604, P0606, P1133, P1441 and P1621 not set; engine speed from 550-3,600 rpm in Closed Loop, BARO signal over 72 kPa, ECT signal from 140-239ºF, IAT signal from -13ºF to +239ºF, MAP signal more than 26 kPa, fuel ethanol percentage less than 88%, VSS less than 82 mph, and the PCM detected the Long Term fuel trim was less than -46% for 16 seconds.

This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)