Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (
-   Troubleshooting/Problems (
-   -   fuel test port location??? Also PO171 code? (

mncmopars 09-22-2010 07:34 PM

fuel test port location??? Also PO171 code?
Hi! Just got my first jeep ever! YAY!! FINALLY!!:) Anyway, she`s an 04` 4.0
She`s showing system too lean bank 1. Not sure what this could be? Checked for vacuum leaks, replaced fuel filter but cant for the life of me find a test port to check psi?? Any clues?? Also sounds like a ""knock" & has small miss when idling but runs great. Not sure where to go from here. She also just had a tune up, timing chain & oil pump. Any help would be appreciated! Thanks!!

Frango100 09-23-2010 07:42 PM

Re: fuel test port location??? Also PO171 code?
1 Attachment(s)
Attached a picture where you can find the pressure test port (item 9) on the fuel rail of the 4.0. Fuel pressure regulator is inside the fuel filter, so that one you already have changed. Could be fuel pump, so good to check the pressure.
Irregular idling could have to do with this as well, but also a good change that your throttle body needs a good cleaning, especially the idle air passage and idle air stepper motor.

Kruul 09-26-2010 08:38 PM

Re: fuel test port location??? Also PO171 code?
You can start with the upstream O2 sensor. Easy and cheap replacement for the DIY. That code is for the sensor detecting to much oxygen. There's a code list here on the site somewhere. Post back your results.

All times are GMT -5. The time now is 03:08 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community