Problem is I cant keep the light off, it seems as though one thing leads to another so i will start from the beginning.
First time light comes on 02 sensor right rear, changed, reset computer lights stays off for a few days and comes on again, This time computer tells me the gas cap is bad, so i replace it reset the computer in the car, lights stays off for a few days, comes on again, by now I am getting a little frustrated and leave it on for awhile with out trying to analyize it, and find out by filling up the gas tank that the gas tank gromment is bad because it has a leak, so i get that replaced thinking for sure I have it whipped now because the grommet is all dryed out and cracked, so anyway the light has come back on after four days running,
Now the only wierd thing that I can see by all of this is that I am getting a black **** build up in the tail pipe, and when I had originally changed the 02 sensor, that the catalytic converter was also full of black **** on the right side, the left side being nice and clean.
When will the pain stop? Any suggestions, or will I just have to keep tackling the codes as they come up? I know I'm whining.
Any help would be appreciated.

This might be important------ 2000 mustang 3.8

 

Did you use a Ford O2 sensor?
The aftermarket parts have been said to be inferior,at least for our cars.
Ford parts are probably more expensive but they are car/engine specific instead of being a generic replacement.

I'd get ALL the codes pulled and repost,these guys are good at finding specific solutions.

 

The codes are, P0411 and P1414, some thing to do with the air intake. I was told that the black **** is because its runnning to rich, that the air mixture is not proper. Could it be the mass air flow system?