What causes DTC Po171, Fuel trim System Lean Bank 1?
04-11-2002, 09:26 PM
#1
TECH Addict
Thread Starter
Join Date: Feb 2002
Location: Lewisville, Texas
Posts: 2,319
Likes: 0
Received 0 Likes
on
0 Posts
What causes DTC Po171, Fuel trim System Lean Bank 1? I got an SES light, the Autotap shows code PO171 Fuel System Lean Bank 1. What would cause this DTC and what's the fix? Thanks for your help,
Mark
Mark
04-12-2002, 01:49 AM
#2
TECH Addict
Join Date: Nov 2001
Location: College Station, Tx
Posts: 2,207
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? Most likely causes would be leak in the exhaust or dead/dying o2.
Less likely would be fuel delivery problem (clogged rail, injector, etc.)
Less likely would be fuel delivery problem (clogged rail, injector, etc.)
04-12-2002, 07:45 PM
#3
TECH Addict
Thread Starter
Join Date: Feb 2002
Location: Lewisville, Texas
Posts: 2,319
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? Thanks Chris,
I have FLP LT's on the car and just had Ed Wright custom tuning installed. I had Ed delete the rear 02 simms so It's either the front ones or a leak. Tomorrow I'm getting custom made cut outs, a Flow Master 3" collector and a set of bullet mufflers installed, so I will have them check the system for an exhaust leak then. Thanks for your help,
Mark
I have FLP LT's on the car and just had Ed Wright custom tuning installed. I had Ed delete the rear 02 simms so It's either the front ones or a leak. Tomorrow I'm getting custom made cut outs, a Flow Master 3" collector and a set of bullet mufflers installed, so I will have them check the system for an exhaust leak then. Thanks for your help,
Mark
04-14-2002, 10:07 AM
#5
TECH Addict
Thread Starter
Join Date: Feb 2002
Location: Lewisville, Texas
Posts: 2,319
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? Hi Trevor,
Yes we finally got the Holley on and it quit leaking. I took it to Nicks yesterday morning and had him install the 3" Flow Master collector, an 18" bullet directly behind it and a cut out right before the Corsa muffler. Then I went over to see Sean and find out why I'm getting the lean bank code. We leak checked the manifold, no leaks and dyno'd it to check the IAC's which were high and cleared the codes. I took it out last night and got a SES light again. I need to autotap it today, I'm starting to get pissed off. I need to find the cause of this and fix it once and for all.
Mark
Yes we finally got the Holley on and it quit leaking. I took it to Nicks yesterday morning and had him install the 3" Flow Master collector, an 18" bullet directly behind it and a cut out right before the Corsa muffler. Then I went over to see Sean and find out why I'm getting the lean bank code. We leak checked the manifold, no leaks and dyno'd it to check the IAC's which were high and cleared the codes. I took it out last night and got a SES light again. I need to autotap it today, I'm starting to get pissed off. I need to find the cause of this and fix it once and for all.
Mark
04-15-2002, 09:46 PM
#6
TECH Apprentice
Join Date: Jan 2002
Location: houston
Posts: 311
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? TTT...I'm getting the same code on both my left and right bank. Just installed heads and cam, and am running into, what I guess is, the usual tuning problems. What's confusing is that my car is running INCREDIBLY rich, so these codes don't make sense to me. Thanks to CHRISB, I will check out my exhaust system becuase on the way home I did notice a pretty bad leak. Any more inputs on this topic??
04-17-2002, 11:21 PM
#7
TECH Addict
Thread Starter
Join Date: Feb 2002
Location: Lewisville, Texas
Posts: 2,319
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? Well,
I did a good leak check of both the intake and exhaust and I don't see any indications of leaks. I clear the code and it comes back after 2 driving sessions. I will check the 02 sensors next, but I don't think this is the problem either. First start of the morning the car won't idle, once it's warm it's ok but I have been getting an occational surge at idle. In park my idle is 1000 RPM and in gear it's 950RPM so I shouldn't be having a problem with the 100 RPM difference in desired idle RPM. I did a h/c change several weeks ago but the PCM should have learned the new set up by now. Could anything other than 02's be causing this? Thanks for your help inadvance.
Mark
I did a good leak check of both the intake and exhaust and I don't see any indications of leaks. I clear the code and it comes back after 2 driving sessions. I will check the 02 sensors next, but I don't think this is the problem either. First start of the morning the car won't idle, once it's warm it's ok but I have been getting an occational surge at idle. In park my idle is 1000 RPM and in gear it's 950RPM so I shouldn't be having a problem with the 100 RPM difference in desired idle RPM. I did a h/c change several weeks ago but the PCM should have learned the new set up by now. Could anything other than 02's be causing this? Thanks for your help inadvance.
Mark
Trending Topics
04-18-2002, 07:54 AM
#8
TECH Apprentice
Join Date: Jan 2002
Location: houston
Posts: 311
Likes: 0
Received 0 Likes
on
0 Posts
Re: What causes DTC Po171, Fuel trim System Lean Bank 1? Well, I did have a bad exhaust leak, which I fixed and cleared the codes. Drove for about 10 minutes and the SES light came back on. Didn't get a chance to check the code yet, but I'm pretty sure it tripped the same codes. I have brand new O2's and the voltage readings off them look normal. I'm confused!! <img border="0" alt="[whiner]" title="" src="graemlins/gr_cry.gif" />
