Question about 1997 Ford F150 Regular Cab

Open Question

1997 4.2 f150 running lean bad thortale responce

1997 4.2 f150 running lean bad thortle responce new injectors fuel filter o2 sensors stumped

Posted by on


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

Rough idle chevy 350

Have you checked/replaced the O2 sensor(s). They produce the data that your computer reads. Bad/clogged O2 sensors will trick the ECU into running lean/rich.

Aug 23, 2014 | 1990 Chevrolet C1500

1 Answer

I have a 1997 ford contour and the diagnostic tool reads left bank lean i was told that could be the fuel filter also my check engine light is on is this normal when the fuel filter needs changing?

It is not a fuel filter. If the left bank was lean the right would be also since the complete engine is fed from a single line to the injectors. Your O2 sensor is probably throwing the code to set the check engine light. The O2 sensors control the amount of fuel fed to the engine. Most Fords use an upstream and a down stream O2 sensor. From what you are describing I am betting your vehicle has way over 100,000 miles on it. The O2 sensors start going out after this point. They are subject to heat extremes and contamination from burned oil deposits and carbon and or fuel additives that you place into your fuel tank. If the code is reading or giving you a "lean" condition more than likely your upstream O2 sensor has bit the bullet finally.

Apr 14, 2012 | 1997 Ford Contour

1 Answer

Failed emissions test running lean

It's really impossible to diagnose something like this. You're running You could have a bad o2 sensor reading the exhaust stream wrong and commanding the PCM to go lean..could be a bad or gunked up injector, fuel pump, fuel filter...too many things to Diagnose like this. +

Apr 29, 2011 | 1999 Chevrolet Silverado 1500

1 Answer

I have 04 f150 fx4 with the 5.4 my check engine light is on code read o2 sensor repaced same one twice andstill say that the o2 sensor is bad why

O2 Sensor codes rarely mean that the O2 Sensors are defective. Most of the time, the O2 sensors are reporting a problem that is occuring somewhere else in the system. If your are getting a code that says "O2 sensor lean" that means that someting on that side of the engine is causing that side to be running lean. This is usually caused by a vacuum leak, but may also be caused by bad injectors or low fuel pressure. If BOTH sides are reporting lean O2 Sensor codes at the same time, it is something wrong that affects both sides of the engine including vacuum leaks in the main hoses tied into the intake manifold including the PCV hose and the Brake Booster Vacuum hose or the brake booster itself, or the Mass Airflow Sensor. Defective Engine Coolant Temperature sensors can also cause these codes. If the code you are getting is a "O2 Sensor Rich" code, it is caused by something that is making the engine run rich. This could be a sticking injector, a failed Fuel Pressure Regulator, or an O2 Sensor circuit that is shorted to voltage, or a malfunctioning Mass Airflow Sensor.
If you want to save a lot of money and frustration, learn this: Fault codes NEVER tell you what parts to replace. Fault codes only tell you which of the many systems monitored by the computer are operating outside their expected ranges or "Window of Operation". It is up to the person diagnosing the vehicle to test the system that is reporting the malfunction and determine the cause of the failure and repair as necessary.

Jan 21, 2011 | 2004 Ford F150

2 Answers

Its running lean an feels like a miss

Check fuel filter and air filter.

Nov 20, 2009 | 1994 Mercury Cougar

4 Answers

Check Engine light is on my 1997 F150 with a small V-8. The tester returns codes P0171, P0172, P0174 and P0175. What does all this mean?

those codes are for lean engine condition look for vac leaks at the back of engine to the pcv valve could hear hissing noise with engine running also check egr valve to be stuck open also when was last fuel filter changed? hope this helps .

Sep 16, 2009 | 1997 Ford F150 Regular Cab

1 Answer

Lack of fuel when accelerating

This might help. It looks like you O2 sencor had gone bad or the signal has and causing multiple mis fire. according to your codes. 
PO171 System too Lean (Bank 1

PO174 System too Lean (Bank 2)

PO300 Random/Multiple Cylinder Misfire Detected

Causes of PO300
Fuel injectors, related wiring, sensors and computer issues
Running out of gas, or poor fuel quality
Evaporative emissions system (EVAP) concerns: fuel vapors leaking into engine
Incorrect Fuel Pressure
EGR system concerns

I'ld start with chaning the O2 sensors first but sheck for bad wire connection. Hope this helps and good luck

Apr 08, 2009 | 2004 Ford F150

Not finding what you are looking for?
1997 Ford F150 Regular Cab Logo

Related Topics:

102 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

76691 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers


Level 3 Expert

5537 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides