So I've been dealing with this P0420 code for about a month. I have no cat so last week I installed a L fitting so the O2 sensor sits further back but the code came back this week. Is there anything else besides coding it out by tune? Thanks!

 

outmotoring has an L with a tad of cat on it, could try that, let me know what works, ill be in the same boat

 

I also put a spacer on the post cat o2 sensor an still get the same code. I have Scorpion header.

I'm half tempted to just ditch the header and go back to stock unless a solution can be found

 

On my previous cars, a spark plug fowler or spacer took care of this. I'll keep trying different things, however after bigger injectors I will be getting a tune so there's that

 

I believe RMW has found a fouler that works, call or email them.

 

http://www.outmotoring.com/mini-cat-...or-spacer.html


could try that

 

I heard back from Jan this morning and the fowler mentioned was for catted headers throwing the P0420 code.