07harleyD

I know these mean that my cats are clogged but what I want to know is, if clogged cats can cause my truck to have a misfire and cause detonation????

BkoJoe

Yes.... if clogged bad enough it may not allow exhaust gasses to exit the cumbustion chamber, also it can cause your o2 sensors to missread and cause a higher a/f mixture...

OkaloosaFX4

Perfect explanation BkoJoe. A lot of folks think the clogged cats actually cause the misfires, but it is indeed the lean condition the PID loops create from sensor misreads. I also understood that if your cats are clogged, don't rush out and get new cats (even the weld-in universals are gonna run you around $700 installed at most shops), because the clog is a symptom, not the root cause of another larger issue... Fix the root cause , then get the new cats...

07harleyD

Thanks guys, yeah I'm pretty sure I figured out the root cause but now I'm left with 2 clogged cats. I picked up some de-foulers from modern performance and I think I'm just gonna chop them out and straight pipe both of them.

Walker Murphey

What was the root cause of your two clogged cats?