Ive had an on going problem with a check engine light thats emissions related. It all started like 3 months ago when i had to replace my ignition control module that set off a blinking check engine light. It went away soon as i replaced then came back like 20mins after steady ever since. i have since replaced spark plugs, both oxygen sensors, and the cat. the light never went off on its own. few weeks ago i disconnected the battery for like 3 hours and then drove it a few days prolly a lil over 200 miles then it showed up again. The cat that i bought was different from my OEM. My paticular car as im sure most of you have heard this before has the one of the O2 sensors on the exhaust manifoltd just before the flange for the cat and one after the cat. The one i bought has on after the flange before the cat and one after the cat. i bought an oil drain plug to plug the o2 sensor hole between the flange before the cat which thread and fit pefectly. the only other probelm is i now have 2 resonators one on the cat pipe just after it but before the flange . then 1 after the cat pipe after the flange. Could that be cause my check engine light prob. basically do I need to get the "correct" cat for it to go away? any help guys would be appreciated i'm two months overdue on inspection!