P0420 pops up after Header kit install

[martinoledad]

they are the hi flow cats that come with the header kit. So do you think this can be helped by tuning. The funny thing is i still hear the sound but the light isnt on anymore.

[Longshot270]

You need a retune after just LT headers or highflow cats. You definitely need one after both.

[martinoledad]

I'm running the truck stock right now. But the new customs are on their way.

[Longshot270]

Ok, I guess just be very nice to the pedal until you get the new tunes.

[martinoledad]

They said the found a small whole around the muffler and they welded that up. But the main problem is just the way the headers are made. They had the truck lifted and you could hear it while it was idleing, but where you could hear it, there isnt any wholes. So i guess its just something im going to have to live with but if you have the radio on, you really cant hear it.

little to late for being easy on the pedal. but ill keep that in mind PHP said they should be ready sometime next week.

[jmt0645]

the noise is part of having headers. mine are the same way. i've forgotten about mine making noise till this thread

[martinoledad]

I kind of figured that. I had Longtubes on my other truck but that has been exactly a year almost and I just couldnt remember if they sounded like that or not.