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2004 Chevy Silverado

Tiny
ABCAUTO
  • MEMBER
  • 2004 CHEVROLET SILVERADO
2004 Chevy Silverado V8 Four Wheel Drive Automatic

Working on a 5.3 liter engine. It is running to rich, (it blow black smoke). It had 4 codes

P0134 o2 sensor ckt no activity (bank 1 sensor 1)
P0171 system too lean(bank 1)
P0300 Multi cyl misfire
P1133 enhanced DTC

We replaced the O2 sensor (front drivers side)
The fuel pressure is at a consistent 60 lbs. Could the fuel pressure be too high?

What is our problem?
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Friday, March 19th, 2010 AT 2:09 PM

1 Reply

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi abcauto, Welcome to 2carpros and TY for the donation

Fuel Pressure (Key ON Engine OFF) 385-425 kPa (55-62 psi) check the fuel pressure while running with vacuum hose removed from the pressure regulator

P0300 is random misfires normally caused by vacuum leaks and contaminated

It is running to rich, (it blow black smoke).

Probable causes of an engine running rich are as follows:

1. Fuel pressure not within specs. Can be cause by restricted fuel return line or defective fuel pressure regulator.
2. Defective Oxygen Sensors.
3. Leaking injectors.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.
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Friday, March 19th, 2010 AT 6:49 PM

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