hi, i have a cbfa engine with a 3" catless dp and i have a 42dd o2 sensor spacer on sensor #3 and i had been fine up untill a couple months ago. the cel comes and goes. i have no idea whats going on with it. i had the dp on for about 5 months with nothing wrong untill now. i figured id adjust the position of the spacer a bit and installed one on sensor #2 as well, but still the cel returns. it sometimes goes away by itself while driving or after a few drive cycles and itll come back while driving or at the begining of a new drive cycle. its baffling me. maybe the sensor is covered with carbon and needs to be cleaned? i sea foamed my engine, but doubt that had any kind of effect, negative or positive. any ideas?