P0171- Lean condition bank 1 and bank 2 - 6 Cylinder Gasoline - Ranger Engine Tech

Home

Recent Topics

New posts

Not logged in - Login | Register

Ford-Rangers.com Ranger Forum > Ranger Engine Tech > 6 Cylinder Gasoline > P0171- Lean condition bank 1 and bank 2

Ford-rangers.com is a discussion forum, a Ranger forum for people who have questions about fixing or modifying
their Ford Rangers or people who just admire their Ranger. Please join and enjoy sharing experiences!

P0171- Lean condition bank 1 and bank 2 #: 2585

Moderated by: Mike69, MaDMaXX,

New Topic

Rate Topic

Posted: Sat Dec 3rd, 2022 04:48 pm

Quote

1^st Post

eegle1
Member

Joined: Sat Feb 29th, 2020

Location: Yakima, Washington USA

Posts: 25

Name: Steve Smith ...

Occupation: Delivery Driver ...

Interests:

Status:

Offline

Reputation:

Reputation Points: 25

Member's Gallery

My Ranger is a 2004 FX4 Off Road 4x4 with the 4.0L V6 and automatic transmission. It has 204K miles on it.

I know that PO171 is usually indicative of a vacuum leak but I've eliminated that issue. The MAF and Throttle Position Sensors have both been replaced more than once. The odd thing is that during the winter months I very rarely have a check engine light. It comes back in the warmer weather and the oddest part of the whole thing is that the truck runs great whether I get the check engine light or not.

Any input would be greatly appreciated!!

Already liked -

Quote

Posted: Sat Dec 3rd, 2022 07:42 pm

Quote

2^nd Post

aroundincircles
Member

Joined: Sun Nov 19th, 2017

Location: Chino Valley, Arizona USA

Posts: 361

Name:

Occupation:

Interests:

Status:

Offline

Reputation:

Reputation Points: 361

Member's Gallery

How did you eliminate the vacuum leak as the issue? There are literal miles of vacuum lines + intake plenum gaskets.

It could also be a bad 02 sensor, a bad fuel injector, or a weak fuel pump. but like 90% of the time it's a vacuum leak. (literally just went through this on another vehicle of mine, replaced a vacuum line just this morning).

But being that it's on both banks? that leads me towards a vacuum leak.

I also did this on my truck when I bought it years ago, I bought silicone vacuum line in an off color (green) and went through and replaced all my vacuum system, so that way I could easily see what I had/had not replaced, my vacuum canister was cracked and leaking so I bypassed it with a check valve, but then my fuel pump was weak, and had to be replaced, and that's what cleared my codes. I had a P0171 and 174.

____________________
https://aroundincircles.net/
1998 Mazda B4000
Mesa, AZ

Already liked - 1 like likes

eegle1

Quote

Posted: Sun Dec 4th, 2022 08:20 am

Quote

3^rd Post

JAMMAN

Owns A Torsen

Joined: Mon Sep 18th, 2017

Location: Grove City, Ohio USA

Posts: 6436

Name: Jim ...

Occupation: 5 axis cnc programmer ...

Interests: RBV's ...

Status:

Offline

Reputation:

Reputation Points: 6436

Member's Gallery

AIC is spot on on his analysis.

If it is generally running fine and doesn't have any misses or loss of power it might be worth grabbing an upstream O2 sensor. I know they are not easy to get to and require a socket but at 204K there has to be a lot of crud on the O sensor depending on how you normally drive. If you take short trips and never give it much throttle then I bet it is just crudded up.

Of course this is based on what you have already replaced.

Bad thing about the O sensor if it is reading lean.... the bank might be running very rich because the system is trying to make up for what it thinks is a lack of fuel. Your mileage would suffer.

Someone really good with a scanner (better yet Forscan) could look at the short term fuel trims and get some clues.

____________________
00 XLT 4WD RCSB 3.GO! JalapeÃ±o
01 XLT 2WD RC Steppie 3.0 auto Silver
The future belongs to those who show up.

Already liked - 1 like likes

eegle1

Quote

Posted: Mon Dec 5th, 2022 04:02 am

Quote

4^th Post

DILLARD000
Member

Joined: Wed Nov 25th, 2020

Location:

Posts: 12

Name: .

Occupation: .

Interests:

Status:

Offline

Reputation:

Reputation Points: 12

Member's Gallery

Could also be PCV hose or elbow cracked+leaking;
P0171 TroubleCode is typical for PCV leaks.

Last edited on Mon Dec 5th, 2022 04:10 am by DILLARD000

____________________
DILLARD000 has a 2001 SportTracJob2, V6~4.0L~SOHC Engin, 5r55e Trans, 1354 4WDTC, LS4.10+OS4.10 Diffs
Details & maintenance links at http://2001fordexplorersporttrac.fandom.com

Already liked - 1 like likes

eegle1

Quote

Posted: Mon Dec 5th, 2022 03:29 pm

Quote

5^th Post

eegle1
Member

Joined: Sat Feb 29th, 2020

Location: Yakima, Washington USA

Posts: 25

Name: Steve Smith ...

Occupation: Delivery Driver ...

Interests:

Status:

Offline

Reputation:

Reputation Points: 25

Member's Gallery

Now that's something to look into. My fuel mileage is pretty poor. Thank you.

Already liked -

Quote

Posted: Mon Dec 5th, 2022 03:32 pm

Quote

6^th Post

eegle1
Member

Joined: Sat Feb 29th, 2020

Location: Yakima, Washington USA

Posts: 25

Name: Steve Smith ...

Occupation: Delivery Driver ...

Interests:

Status:

Offline

Reputation:

Reputation Points: 25

Member's Gallery

With 204K on the engine replacing the vacuum lines might not be a bad idea in any case. Thank you.

Already liked -

Quote

Posted: Tue Dec 20th, 2022 05:54 pm

Quote

7^th Post

eegle1
Member

Joined: Sat Feb 29th, 2020

Location: Yakima, Washington USA

Posts: 25

Name: Steve Smith ...

Occupation: Delivery Driver ...

Interests:

Status:

Offline

Reputation:

Reputation Points: 25

Member's Gallery

What is really puzzling about this is that the condition is not present when the daily air temperature remains below 35°F. Is there an ambient air temperature sensor or something else that could be the issue?

Already liked -

Quote

Current time is 03:50 pm	Top
Ford-Rangers.com Ranger Forum > Ranger Engine Tech > 6 Cylinder Gasoline > P0171- Lean condition bank 1 and bank 2
Users viewing this topic

PHP Version: 8.2.28

Server version: 10.6.22-MariaDB