http://www.jbodyperformance.com/new/PartDetails.php?partId=288&catId=288&catName=JP0288

JBP sells 3 stages of cams for the Ecotec but they claim the stage I is ECM friendly and throws no codes.
The stage 2 will throw codes at idle and is not ECM friendly.
The stage 3 is supposedly just as friendly as the stage I.

What am I missing?


2003 Sunfire with 2 1/4 inch turbo muffler, 2 1/4 piping, 2 1/2 inch resonator, a 2 1/4 inch catalytic converter, 2 1/4 inch down-pipe, a ported LSJ manifold, E-bay strut brace, and an AEM true cold air intake NOPI edition.

I would imagine its due to the difference in the duration/ valve lift between intake and exhaust. The others are equal or only 2* off, whereas the stage 2 has a 4* and 2* difference between intake and exhaust. I may be wrong, but i believe the bigger the difference, the rougher the idle, hence the codes at idle.

cams installed without tuning is a waste. ecu friendliness shouldn't be a concern..

cams need to be tuned in, it throws off the VE map pretty bad, and jbody ecus can't "learn" flow mods.