Engine Mods and CELs
 

I am adding engine mods one at a time. I have installed a Perrin intake. Next will be cat-back. Then over and down pipe and then possibly headers. Am I correct in saying that I will get a CEL when the ECU is no longer able to make the necessary adjustments for the modifications? I am not referring to extracting the most power with a tune. I am wondering at what point does a tune become a necessity.

Ta.

I've only seen CELs in two scenarios:

1 - Intake is messing with the MAF signal enough to throw it off
2 - A header without a primary cat can throw off the O2 reading. A lot of guys have run spacers/washers to get rid of the problem. If you get a header with a primary cat, it shouldn't be an issue.

+ some headers manufactures are coming up with other ways to extend the sensors or block it, but considering you'll run a header and all other supporting mods i bet u'd be in need of a tune which when you do you could remove the CEL code