DTC P0171 Fuel Trim System Lean Bank 1; can't find a leak
#1
TECH Enthusiast
Thread Starter
Join Date: Jul 2005
Location: Herndon, VA
Posts: 732
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I'm trying to get my LS1 to pass VA ODB2 emissions test before swapping in a new LS6 crate motor. I've fixed all the other codes I was getting (replaced O2 sensors and cats), and now I've just thrown DTC P0171 Fuel Trim System Lean Bank 1. I did a quick hose inspection and smoke test, but can't find any leaks. I'm going to try again when the car cools off. While I was looking at live data running through the tests, I noticed the LTFT's were showing about +4.99. I reflashed it with the stock tune and deleted all the old DTCs before replacing the Cats and O2 sensors, but I had been running a Predator tune for a while. Of course, since the O2 sensors and cats were bad (and sooty as heck), it was probably pretty rich before I fixed them.
Do you think I really have a leak, or is the system just taking a while to relearn\recover? I was also going to delete the DTC and run it some more to see if it comes back.
Since it's only for Bank 1, does that mean the MAF and fuel filter are OK? BTW - it's an SLP 85mm MAF...
Do you think I really have a leak, or is the system just taking a while to relearn\recover? I was also going to delete the DTC and run it some more to see if it comes back.
Since it's only for Bank 1, does that mean the MAF and fuel filter are OK? BTW - it's an SLP 85mm MAF...
#2
TECH Enthusiast
Thread Starter
Join Date: Jul 2005
Location: Herndon, VA
Posts: 732
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
...there was no leak; it just took a couple of clears of the DTC + 75 miles more driving to make it stay gone.
Now that I've got my ODB2 certificate I can get my registration stickers, and throw the LS6 in it...YEAH!...and I won't have to take another ODB2 test for two years.
Now that I've got my ODB2 certificate I can get my registration stickers, and throw the LS6 in it...YEAH!...and I won't have to take another ODB2 test for two years.