Running lean bank 1 and 2

2008 CHEVROLET AVALANCHE
170,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
Avatar
CSTEINER866
  • MEMBER
  • 1 POST
Just got it out of shop who claimed to have sealed all leaks. Two days later running lean again. No noticeable smells or performance issues just engine light.
Jun 12, 2019 at 3:05 PM
Advertisement
Avatar
KASEKENNY
  • ✓ASE Certified Mechanic
  • 18,907 POSTS
  • ASE Certified Mechanic
Hi CSTEINER866,

We would need to confirm it is running lean with checking codes but the fact that it is running lean on both banks after they "sealed" the engine, I would have to assume they missed something or their repair failed.

Did they give you a list of what they sealed and how?

If you have a lean misfire, the most likely cause is vacuum leaks so you can check this by spraying some carburetor cleaner around the engine to see when the RPM raises. The detail is explained in these guides:

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please let me know if you have other questions or let me know what detail they gave you.
Jun 12, 2019 at 3:21 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.