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  1. Lots of codes don’t know where to start

    02-09 Vortec 4.2L I-6 Engine and Drivetrain
    Well after getting my envoy back together after cleaning the tb and clearing codes and a good few days of driving like a dream My truck idles rough smells like gas again then sputters and randomly stalls This time I got codes P0014 vvt solenoid? P0172 rich P0420 catalyst efficiency P0171 lean...
  2. Code P0172 sputtering stalling rough idle

    02-09 Vortec 4.2L I-6 Engine and Drivetrain
    Hello everyone I recently saved a beautiful black 2003 envoy 4.2 with 200k from the crusher I need a little help getting her to run perfectly When I first drove it everything was fantastic no check engine just a little sluggish and a service 4wd light on. In the last few days of driving I...
  3. 2004 Trailblazer EXT 4.2L 4x4 High RPM and Engine misfire under slight load

    OEM Issues
    I bought this Sept 2017 with 134,000 miles on it. Body is in pristine condition and has all the service records from day one. Within the first 1,000 miles I was getting a MIL light and code P0128, so I switched out the thermostat. That seemed to solve that problem. This spring when the weather...
  4. Throttle Position & Air Intake Sensor Codes

    OEM Issues
    I've been browsing this site for a few months now and finally decided to join. Special thanks to everyone who keeps posting. I have three error codes from my trailblazer: P1120, P1220 (throttle position sensor circuits 1 & 2) and P0172 (system too rich bank 1). I had gotten the P0172 code a...
  5. 03 Trailblazer (4.2l) P0172 (after Fuel Pump and Coil Replaced)

    Hello Everyone! I am having a nightmare with my 2003 Chevy Trailblazer. Here is the history of the current repair so I can get some advice from you FINE GENTS hopefully. OK, so I had the fuel pump bust a sending line the other day which dumped all the gas out and noticed it in a parking lot...