I asked about power gains or loss in a different post and pretty much everyone said nothing to gain. Does anyone have proof from a wideband of back to back cat and decat on the air fuel ratio? I bought a take off head pipe and still want to get rid of the cat. I've seen other posts about it. Some said gets richer, some get leaner but no proof from a wideband or dyno. If the information is out there I haven't found it.

 

I can not answer your question but I have a friend who decatted his pipe and installed Cobra NH slip ons and tuned with a power vision and the damn thing halls *****.

 

If you look at fuelmoto dyno charts they show a gain with the catless headpipe but nothing you'd ever feel. Less heat and better sound made it worthwhile for me.

 

I couldn't find one for just removing the cat. I'm not worried about a power gain. Just want to help it run cooler. I want to make sure the air fuel ratio doesn't go lean.

 

There to lean from the factory.... stock.

 

It definitely runs cooler and as far as the AFR going lean, that's where a good tuner comes in.

 

Catless headpipe on its own prol won't make much difference to the heat. You have to add a little fuel. HD tuner is still EPA compliant so go with an aftermarket tuner and risk your drivetrain warranty while running better and cooler or stick with EPA....

 

Hope this doesn't turn into another warranty thread!

 

A good tune will cool it down better than removing the cat and increasing airflow without appropriate recalibration of the fueling.
It should/would run fine (albeit lean as delivered) at cruise due to the O2 sensors. What the system can't do is compensate in the high load/rpm areas. Those areas do not use the O2 sensors to trim fuel so logically it must run leaner/hotter.
Bob

 

^^^Yep!^^^