Hello,
I picked up this 1997 Ranger, v6, and once I drove away and signed over some problems showed up.
1. The check engine light came on. I stopped at AutoZone. they scanned it and told me I need a new PCV valve or hose. The one currently installed looks brand spanking new, (from what I gather to be the PCV valve) I guess the owner cleared the code before selling it to me. Where should I start looking?
2. Arriving home I noticed some brown sludge looking like mud in the coolant reservoir. Looks like it can be dexcool? So I want to try flushing the cooling system. What was concerning to see... was there wasn't much coolant. What do?

 

Which engine does it have?

 

It has the 4.0. also to add detail its a 2wd.

 

What is the actual code? Most codes have several different causes. And sometimes people get their acronyms mixed up. PCV, EGR, MAFS, EVAP, etc. I'm not sure a 97 Ranger V6 is sophisticated enough to set a PCV code.

On the coolant, I'd fill it up with water, drive it, and see what happens. Water is for short-term inexpensive troubleshooting only, it will allow corrosion in the long-term.

Good luck with your new problems.

 

 

That is what we call a "lean code". That's never the PCV valve itself but it could be the hose to the PCV valve.

It's caused by a leak in the air intake system after the MAF sensor, letting in unmetered air. Could be the manifold gasket, could be the air inlet hose after the MAF sensor, could be a cracked PCV hose.

Check the big air inlet hose to the throttle body after the MAF sensor for any unplugged hoes or cracks. Check the PCV hoses for leaks or cracks. Check the brake booster. Check all of the vacuum lines that you can find.

p.s. the old intake leak test of spraying carb cleaner around the leak areas doesn't work well because the computer is too fast to hear the RPM change. You need "live data" to try that test to see the change in fuel trims.

 

 

https://www.obd-codes.com/p0171

A code P0171 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor
Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve Failed or faulty oxygen sensor (bank 1, sensor 1)
Sticking/plugged or failed fuel injector
Low fuel pressure (possible plugged/dirty fuel filter!)
Exhaust leak between engine and first oxygen sensor

Possible Solutions
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include:
Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace/repair as required
Inspect all hoses and connections in the air intake system Inspect and/or test the intake manifold gaskets for leakage
Check for a dirty fuel filter and proper fuel pressure
Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool If you have access, you may want to run a smoke test

Read more at: https://www.obd-codes.com/p0171
Copyright OBD-Codes.com

 

The page with the "Solution" on it does not contain the P0171 code. Kind of odd. The code and the "Most Likely Solution" are not shown to be connected.

Anyway, the link I provided is my favorite for researching codes. Pretty thorough and prioritizes by likelihood. Not impressed with FixFinder - no offense.

 

Thank you. That is at least some direction for me to look. I will update some pictures when I get a chance of my findings.

 

In your post #5 it shows P0174 as the secondary code. This is also called a pending code. It means that the problem is affecting both sides of the engine's intake system. Typically one side sets before the other, this usually means the problem is minor and has just passed the code-setting limit. If it was major both codes would be set.

Knowing this is important in that a single O2 sensor problem on bank 1 (P0171) would not affect bank 2. So, focus on the things that affect both sides like the MAF sensor or intake system leaks. I actually bought an O2 sensor when I had a P0171 code before getting a code reader and seeing and learning about the P0174. I still have the sensor, waiting for when it's needed. (Should have bought two, the price has gone up by 50%).

Also, the code just means that a problem has been identified via the O2 sensors. But the engine will continue to run just fine for many miles, with no damage. It just means the computer has to shoot more gas than expected through the injectors to get the O2 sensors in-line.

 

It’s been a while since I kept up with OHV 4.0 trends, but I recall intake manifold gaskets being an issue as well as injector o-rings tripping those codes.