Do all aftermarket exhaust trigger a CEL at some point?

 

Im going to say 'more than likely' if the car is tuned / flashed. Stock cars with an exhaust might not ever generate a CEL.

There are many CEL's of course that are exhaust related, the most common seems to be the 'running too rich, post cat' code. Easy fix with oxygen sensor extenders or via some tuner flashes themselves.

 

No, only 'some'.

 

Tunner flashes is the only one that guarantee you that don't show the CEL related with increased exhaust flow. Sensor extenders may do the trick but it depends of the disposal of the cells inside the cat and the grade (100, 200 or higher). Top brand cats are at this moment at the same price of a flash. So if you only want basic mods: OE exhaust system with deleted cats + good flash, it can free up to 100hp. Plus the OE muffler has the best insulation for catless (dronning free) and only straight pipes will improve exhaust flow over that.

 

Not sure flashes are the only way to guarantee not getting a CEL. Some systems (like Europipe) are engineered with hi flow cats (100cpsi) that never generate CEL's - I'm sure there are others but I know for a fact that with Europipe there are no CEL's..and the O2 sensors are just plug and play when you install the EP - no extensions, etc. needed.

 

"depends of the disposal of the cells inside the cat and the grade (100, 200 or higher). "
That is why their systems cost almost $5k... My post was about power wise vs money.