99 Ford Ranger Troubleshooting question

Reply Subscribe

Thread Tools

Search this Thread

Nov 6, 2009 | 12:08 PM

cliftonfts

Thread Starter

New User

Joined: Oct 2009

Posts: 18

Likes: 0

99 Ford Ranger Troubleshooting question

I have a 1999 Ford ranger 4.0L EFI 4Wd
Here is the a link to the values I was receiving with a OBD scanner . I got trouble codes PO171 and 174 running lean on banks 1 and 2. I have recently in the past few months change MAF sensor, 2 O2 sensors, fuel filter and air filter and spark plugs. I even tried checking for a vacuum leak by spraying carburetor cleaner around the engine to see if it idles higher. But I can't seem to find a vacuum leak. Thanks for your help.

cliftonfts' Home Page - Road Runner Personal Home Pages

Nov 6, 2009 | 08:11 PM

g_k50

Cargo Master

Joined: May 2004

Posts: 3,007

Likes: 5

Check the wiring on the transmission.

P0171 and P0174 are both fuel system DTC's The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit.

Possible causes are Fuel system, Excessive fuel pressure, Leaking/contaminated fuel injectors, Leaking fuel pressure regulator, Low fuel pressure or running out of fuel, Vapor recovery ststem, Induction system, EGR system, Base Engine.

Nov 6, 2009 | 08:18 PM

g_k50

Cargo Master

Joined: May 2004

Posts: 3,007

Likes: 5

Helm Inc has the Powertrain Control/Emissions Diagnosis Service Manual available for the 1999 Ranger, you can rent it for 72 hours for 10.95, buy the paper copy for 180 (it's worth it).

Nov 8, 2009 | 02:07 PM

pawpaw

Moderator

Joined: Jan 2004

Posts: 13,851

Likes: 111

From: SW Va

Add the PCV valve to your suspect list, especially if it's due, or past due, or hasn't been changed for a while. if it's sticking open, it'll cause a non-planned for vacuum leak!!!!