low idle, misfire after air filter?

[dandog2500]

Hello, Just had a quick question. I have a 2002 max with 155k. I just changed out the engine air filter (Fram) and added some oil with some engine restorer because the oil was getting low. After driving about 30 miles, I am getting a low rough idle ( 500rpm). It is also misfiring, (blinking CEL). is this coincidental or did i do something wrong? I assume its fixable, however I might be at a decision making point with the car.

[NutriaforBreakfast]

Try to work the problem from the CEL reading first. Do you have a
code reader?

[dandog2500]

Last I checked it was an bad o2 sensor b2s2, then a b1s2 high voltage.

[dandog2500]

update on the CEL. one code was for high voltage 02 sensor (b1s2) the other was for crankshaft position timing over advanced or system malfunction. Dont know if that would cause a rough idle around 500 rpm

[NutriaforBreakfast]

The computer might make the engine run rich with a bad o2 sensor
Certainly a bad Crank sensor would-seems like if this was bad the
engine wouldn't even turn over
With 155K miles, the o2 sensor probably needs replacing anyway or
you can try to see if it is working but it won't be easy I don't think
Have you tried the Floor Shop Manual?