Disconnect EVAP???

[Bmwtvboy]

MY X is old. It has been great. Recently, EML, never had that light on before. NEVER. Came on while SES light is on. X is at temp.
Rich codes (P0175/172). I noticed the X was running so smoothly over the past 2 months. I changed to regular gas and still got great MPG. No issues. After it sat for 2 hours, started up, no EML, but SES stayed on. Checked codes, cleared them out.
If it is the O2 sensors(4)@165Kmiles, or the Cats, they're original 249K miles.
How do I disconnect the entire EVAP system? I found the head/breather plug on Amazon. What about the Sensors? Do I need special software to close it down? I really don't want to spend hundreds on cats or O2/s at this point. Updated the DVanos at 200Kmiles. Recently did tranny/filter/fluid and it drives/shift beautifully. 90% of this X is original '01 mechanics/electrical systems.
What are my options?
I spent a small fortune to fix the trifecta, but it only worked for about a year. Trifecta back on, but the X drives great. Realize, I am in FL. A/C system, original and works ice cold.
What to do? I really like this old X. I have done much of the work myself.
I appreciate any advice and counsel. You guys have always been great.
I don't have any fancy software / diagnosis tools yet. Just a small scanner.
Thanks.

[e39_touring]

You're running lean, not rich. Most likely due to vacuum leaks - check your intake boot for tears and check all the hoses under the intake manifold.

Evap can be disabled for free by applying the factory 'eu2' tune.

[Bmwtvboy]

Odd, I thought those codes were rich. I have had lean issues before and traced to vacuum lines off EVAP. I will do a complete inspection of air intake to TB n the ICV. It's been at least 50 K miles. Thanks..

[upallnight]

Originally Posted by e39_touring

You're running lean, not rich. Most likely due to vacuum leaks - check your intake boot for tears and check all the hoses under the intake manifold.

Evap can be disabled for free by applying the factory 'eu2' tune.

Lean codes are P0171 and P0174.

[e39_touring]

Originally Posted by upallnight

Lean codes are P0171 and P0174.

Yep, upallnight's absolutely right. Yours are the too rich codes. I just went through the too (two) lean codes about a year ago and didn't check the numbers.

The one thing I can add is that since you're getting the codes on both banks, it's likely a global problem. Think maf, fuel pressure, air filter restriction, etc. instead of individual cylinder stuff like plugs, coils, etc. I don't think an evap problem will trip those codes because an evap problem only causes a temporary rich condition not long enough to trip p0171/4. You'd also be getting evap codes if there was an evap problem, which you didn't mention.

[trentcdrums]

I changed my Cats from a set on Amazon, direct fit too for a few hundred and replaced 02 sensors with OE all in my garage floor. But you need to EuroTune with NCS Expert with the way youre trying to go..

[upallnight]

Most obvious question, when did you last change the air filter? A clogged air filter will limit the amount of air entering the engine, hence it can cause a rich condition.

Better yet what is the air flow through the MAF? You can get a scanner that can read the MAF air flow. Post it here. Post g/s for the MAF, I'm use to g/s.

[Bmwtvboy]

Later today I can check MAF with scanner. I did do a complete clean up to the TB, ICV. The air filter was a little thick, washed,rinsed and dried. Sprayed the Maf sensor. Seems to be a huge improvement. BTW, is that a special schrader valve attachment? AZ gives out a free fuel pressure gauge for testing.