Soon I will be installing a magnaflow 15620 catback in my 95 Z28. I read somewhere on the net that because the magnaflow catback has no backpressure it will trigger the ses light. Is this true?, did it happen to anyone on the forum?. I read to disconnect the negative battery terminal before installing the catback. When the installation is complete reconnect the negative battery terminal to the battery and the pcm will recalibrate for the new catback.

Thanks in advance

 

you dont need to disconnect the battery, and the pcm doesnt recalibrate itself, but it doenst need to be with just doing a catback.The only thing that is really changing is the muffler, and whoever told you that information doesnt know what they are talking about.The SES light will not come on unless there is something else wrong with the car.LT1 engines run on a negative back pressure system, but there has been a debate for years about backpressure.NHRA dragsters run will just headers and they dont have any problems.I have driven my car and even had it dyno'd with open headers and i didnt lose any performance at all.

 

I was going to say: I've had my car running with open headers, which is about as open as you can get. No need for "backpressure"

 

Mine goes on this weekend, and the magnaflow site shows both a torque and hp increase on a dyno with just the exhaust change.