2001 Ford Ranger



January, 7, 2009 AT 7:09 PM

Engine Mechanical problem
2001 Ford Ranger Four Wheel Drive Automatic 88200 miles

When reading the Diagnostic Codes I come up with
P1401 Heated Catalyst Current too High During Heating (Bank 1)

P0171 System too Lean (Bank 1)

P0171 System too Lean (Bank 1)

P0300 Random/Multiple Cylinder Misfire Detected

Can you give me some idea of just what these codes mean.
If it is something simple I would like to fix it myself.
Also, I just installed a new EGR after reading a question in your website from someone that was having a problem identical to mine. The new EGR valve did not seem to have any effect.
Thanks for any help


2 Answers



January, 7, 2009 AT 7:54 PM

Hi there,

P0171/174 mean your ratio air/fuel is messed up. You have too much unmetered air reaching your engine.
P0300 is a random misfire codes. Several of your cylinders are misfiring. It's probably the result of the extra air. If you fix the P0171/174 codes I'm confident it'll fix P0300 at the same time.

Okay, I can't guarantee it for sure, but a lot of time with Ford cars, when you have these codes, the culprit turns out to be the DPFE sensor. This sensor is part of your EGR system. I'm not sure where it is located on a 2001 Ranger, but I'm thinking if you look at your egr tube (the pipe that connects the exhaust manifold and the egr valve), the sensor is probably connected to it by two small hoses. By the way, that's what the P1041 code means: something is wrong with your DPFE sensor.

Take a look at it and make sure the vacuum lines are connected; but it's very possible you'll have to replace the sensor (around 50-60 buck for an aftermarket one I think).

Hope this helps.



January, 7, 2009 AT 7:55 PM

You have a lean fuel condition can be caused by: * Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

P0300 Random Misfire normally points to vacuum leak and bad fuel

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