Car problem

Is the EVAP code the only DTC you got.. with a scanner? Or did it have any other PXXXX codes? It's possible that the EVAP can make it lose power, but unlikely. If the solenoid is stuck open it can draw fuel and make it run very rich. If you see black smoke, it is running rich, Have a look at this, click for full screen

Yeah the evap code is the only one I got there is no black smoke but there is black soot in the pipe and it does seem like it used more gas

My masters air flow screen was black when I cleaned it

That's all I can think of, not being at the car.. Not trying to make excuses but from behind a keyboard it's difficult to make a diagnosis. There are guys that know ore about Mustangs than I do, I bet they will chime in shortly. Good Luck and Happy New Year!

The Mass Air flow sensor between the intake duct and Air filter? Somehow it sounds like oil is entering the intake

The right there but it was a light dust of black on the screen

If it's never been cleaned before in a '99 that would be normal and expected .... there is no filter before it, that intake air is raw.... that will happen. I take back the oil entering intake. I will do some research

What engine? 3.8 V6?

Yes 3.8 v6

I replaced a bad line and egr valve and ran sea foam through nothing it's got worse with the idle now

It shakes really bad now

I looked all around for the symptoms you describe, and came up with nada for a real answer. But you have a misfire in one or more cylinders, that much I can say. And worn motor mounts will make a vibration or shaking much worse with a misfire. Have you done any engine work lately, such as spark plug wires? If they did not get put back where they belong that will do it. And the black soot points right back to running rich. One possibility is it's not going in to closed loop. On a cold start the 02 sensor signals are ignored by the PCM to run rich until the coolant gets up to a pre-set temperature, then goes in to closed loop and the PCM uses the signals to set fuel/air trim. But that is a wild guess.

But that never happen till I changed the egr

It runs better cold then warm

In that case, running better cold leads me back to not going in to closed loop. You are getting the proper fuel/air trim cold, but same a/f trim at operating temp is too lean. Suspect vacuum leak now

I don't know how the EGR will enter in here, but I will try to find out

C'ome on guys, little help here for this guy? I feel stranded, Mustangs are not my specialty.... :~)

Try pulling the air filter out and running it, I've seen the plastic cap on them break free and cap the intake tube at the air meter housing.

I guess I'm just gonna take to a shop and get an answer