My wife's 03 expedition has had the check engine light on for a few days now. I replaced the IACV on the engine and replaced the fuel filter. Of course I made sure to disconnect the battery. Anyway I had her run it over to Autozone to run the computer on it and she came back with two codes P2195 & P2197. They seem to both lead to the O2 sensor. I called to find out there are four of them on the 4.6! What the heck! Anyway I guess I am seeing if anyone else came across these codes and did they replace all 4 at once or not. The truck runs for crap, it idles reall rough and stalls at traffic lights. I have the coils on order from ebay and will be doing a tune up next.

Any help would be great!

 

Okay, gotta love the internet....I went and find out the definition of the codes...It came back that Bank 1 Sensor 1 and Bank 2 Sensor 1 are both failed to run lean. Now from what I hear, there is one before the cat and one after. I assume the "banks" are either side of the exhaust pipes, so, I would guess that sensor one is before the cat and maybe sensor two is after the cat? I am not sure and at $50 for each sensor I really don't want to be buying parts needlessly.

 

Bank one is the side with the #1 cylinder and bank 2 is obviously the other side of the engine. On both banks, sensor 1 is before the cat (upstream) and sensor 2 is after the cat (downstream).

 

Great! I thought that but before I make the purchase I wanted to be sure!

Thanks!

 

WHOA!

DO NOT START REPLACING PARTS unless you have an unlimited budget of money to waste.

Do NOT replace all four (OR ANY) of your O2 sensors, they aren't bad.

Here's the list of the possible causes for your fault codes. Since you got the same code for both banks, look for an occurrance that affects both banks.

Electrical:
Short to VPWR in harness or HO2S
Water in harness connector
Open/Shorted HO2S circuit
Corrosion or poor mating terminals and wiring
Damaged HO2S
Damaged PCM

Fuel System:
Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system

Induction System:
Air leaks after the MAF
Vacuum Leaks
PCV system <--------Start here!
Improperly seated engine oil dipstick

EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR

Base Engine:
Oil overfill
Cam timing
Cylinder compression
Exhaust leaks before or near the HO2S(s)

FWIW, I'd suggest you first approach it as if the fault codes were the older "lean" combo of P0171/P0174 which is an FAQ.

Steve

 

I agree with the above. O2 sensors take readings. Just because they read lean or rich doesn't mean they are defective. It means that something is causing the engine to run lean or rich on the indicated bank. O2 sensors generally last a long time, unless the problem isn't fixed, and then they build up with gunk and can't take good readings anymore. Don't forget about your normal maintenance, that has been required since day one. Electronics didn't change that.

 

Okay, I screwed up....I replaced the driver side O2 sensor..The damn passenger side still in there, I have no idea how to get one out! I am out of ideas, I hate friggin electrical bugs. I saw the one list of things that it could be. See it is running as if there is a vacuum leak runs rough and like jumps when you are sitting at a light with the brake on. I am use to carbs on gasers and my other vehicle is a deisel, so this is a pain with injection. I read about vacuum leaks in a tube of some sort..I thought that computers are suppose to help in chasing bugs down. My wife is starting to get pissed at me. I am fairly mechanically incline and this one I just can't figure out. I will take a look around here for guidance. I am still going to do the plugs and coils, but I don't think that would lead to a lean mixture, I would think that would lean towards a rich mixture reading if the plug wasn't sparking and burning properly.

Any help would be great....

 

Remember that the O2 sensors are not 'fuel' sensors so they don't measure rich or lean fuel. They measure the amount of O2 in the exhaust and from that infer the mixture.

As Steve pointed out, all four O2 sensors don't bite the dust at once (unless maybe you filled it up with diesel fuel )

And all COPs don't go bad at once. Ditto for all the plugs.

A missfire will not consume the oxygen in the fuel mixture so the O2 sensor will see excess oxygen in the exhaust and drive the fuel injectors richer to try and compensate. If the LTFT (Long Term Fuel Trim) has to go beyond +22+24% rich to compensate the PCM will set a code and turn the light on.

And a sever misfire would set a misfire code. Do you have any other codes?

If your scan tool can look at the freeze frame data that will give you a hint. If the freeze frame data shows the code was set at low RPM and/or light throttle, it is prolly a vacuum leak. If the data shows the code was set at higher RPM or at heavy throttle it is probably a fuel delivery problem. And if your scan tool can monitor the LTFT for each bank it will tell you if the problem still exists or has gone away.

Check out Steve's list of possible problems and treat it like you have the famous P0171/P0174 codes. Its something that is effecting both banks at the same time. PCV elbow? Dip stick fully seated? Adequate fuel pressure? Dirty MAF? Air leak between the MAF and the TB? Intake manifold leak? And on and on

Good luck - and let the list know what the fix ended up being.

 

All I have to say is "THANK YOU!"

You would think that fixing my wife's car was the best Valentine's Gift I could have given her! After reading the post and the possible items it could have been, Saturday morning I popped the hood and not even 5 minutes I located the issues. The 90 degree rubber eblow had melted through on the back of the PCV valve. Go figure. Well it being Saturday and all the parts departments for FORD being closed around me, I took a ride over to PepBoys and spoke to the guy behind the counter. The elbows that they had in the "help" isle didn't work so we walked around the pre formed hoses. I was able to locate a heater hose for a Chrysler that would work perfect. Got home made some adjustments to the length, slipped it on and it purrs like a new kitty! God you guys are great! The best part is the O2 sensors that I bought the week before, took them back and got my money back! a simple $13 fix!

Thanks again to everyone who assisted!

 

same thing happened to me..........