Troubleshooting GM trouble codes

Tiny
SKIRACER1
  • MEMBER
  • 2002 CHEVROLET AVALANCHE
  • V8
  • 4WD
  • AUTOMATIC
  • 138,000 MILES
Trouble codes PO131 & PO151 banks 1&2 O2 sensors #1 keep setting a trouble code while hwy driving. Also sets pending codes for the #2 O2 sensors on both banks. I replaced both #1 sensors w/ new OE sensors but codes still come on with heavy accelaration on hwy. Also seems to lack power unless under full throttle. Can you help me with a diagnosis? This is a 2002 chevy avalanche 4x4 w/5.3 liter. It was also recently setting a code for the MAF but I cleaned it and the code has not returned.
Wednesday, February 23rd, 2011 AT 11:06 PM

1 Reply

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
If you have that code, check your fuel pressure. It should be 55-61 psi. Then checkyour fuel regulator. Clane the throttle plate with chokecleaner on both sides as they gum up. Also check for a vacuuum leak. Check all hoses air and breather elements for having holes or not connected. These can also set codes.
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Tuesday, March 15th, 2011 AT 11:06 PM

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