Bank 1 and 2 lean codes

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

kendrick newborn

TYF Newbie
Joined
Nov 14, 2024
Posts
2
Reaction score
0
Hey everyone, I have 2004 chevy tahoe 5.3 and it keeps throwing bank 1 and bank 2 lean codes. The only thing that I've noticed is it has a inconsistent engine shake at idle, I did look for vacuum leaks but I haven't found any yet. Has anyone delt with this issue before? The only thing not stock is the previous owner installed a cold air intake
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,826
Reaction score
24,051
Location
Elev 5,280
The OE air intake is already a CAI, so there's nothing to be gained by changing it to aftermarket, other than more noise under the hood and a potential dirty MAF.

In addition to the other suggestions of a vacuum leak or fuel pressure issue, I'd add that perhaps unmetered air is getting in after the MAF and before the throttle body. Carefully inspect that CAI plumbing for any leaks. Best thing to do is change it back to OE.

Also, the MAF may be dirty or may be reporting inaccurately.

A good bidirectional scanner and some knowledge about how the fuel trim system works would likely show the cause of the problem. You may need to see a good doctor.
 

Forum statistics

Threads
132,234
Posts
1,864,454
Members
96,781
Latest member
Ykn11Cg
Top