basically, i put on a test pipe with a CEL fix and still had a CEL shown. the ap1 vs ap2 have different secondary o2 simulator part #'s. my 07 has a different part # than both of those. i have read ap2s generally have more sensitive secondaries...

1. will 2 simulators work? ie) 4 anti-fouler plugs?
2. is the secondary o2 reading based on the ecu? or more on the sensor? for example, does the o2 sensor dictate the ecu or vice versa? i ask because: will an ap1 secondary o2 sensor solve my CEL problem?

Thanks in advance.

 

4 anti foulers won't work.

What year car do you have?

What sensors are installed and are you using an 2 anti foulers stacked?

The most important question, What Code is stored from the CEL?