So I just finished the timing job on my Ion. replaced sprockets, chains, guides, tensioners, water pump, plus the fixed access bolt. (that's what broke in the first place) I got it timed correctly but the car still seems to idle rough and backfires out the exhaust. Could this just be caused by my eBay sparkplugs and coilpack? And would replacing the ICM from my old module onto the eBay module fix my rough idle and start?

 

Possibly, was it running and rattling or had it quit running before the repair? Did you verify compression after installing the new components?

 

Before the repair it was running rough but it hasn't had a misfire code ever since I changed the valve cover gasket along with those eBay coils in June. Haven't checked compression yet.