Loping idle lean fuel mix on left bank & right bank?

Tiny
FRANK HERDMAN
  • MEMBER
  • 2001 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 75,000 MILES
Trouble code lean fuel mix on left bank & right bank. Have replaced iac valve & tp sensor. Also has a loping idle. Replaced all 3 oxygen sensors, pcv valve & spark plugs. Still have loping idle. Idle rpms are 575-650. Vacuum psi 19 steady.
Wednesday, December 12th, 2007 AT 7:38 PM

2 Replies

Tiny
BLACKOP555
  • MECHANIC
  • 10,386 POSTS
The lean bank code usually means a bad O2 sensor, replace and your problem shoudl go away.

Can you provide with the codes?
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Wednesday, December 12th, 2007 AT 8:23 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
I don't think so, it sounds like the fuel pump is going out or the fuel filter needs to be replaced, here is the location of the fuel filter and a guide to help you understand what the problem is.

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

Fuel pressure should be

Key On Engine Off 41-47 psi

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Check out the images (below). Let us know how it goes.

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Tuesday, August 27th, 2024 AT 2:01 PM

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