Will the CEL cause the truck to run badly?If you don't have a tune that has turned off the rear O2 sensors, you will.
No.....it won't turn into a Ford!
Problems with the front sensors is a different story.
I had them turned off when my computer was flash tuned. Never had a problem running the JMB mid pipes. All 4 O2 sensors were in the pipes just like stock.
No.....it won't turn into a Ford!
Problems with the front sensors is a different story.