P0420 & p0430

[ippielb]

So my cats were plugged up and were causing my truck more harm then good so i had to remove them, but couldnt afford the money at the time to put new ones on. I could afford the $30 in pipe, but not the $200 cats. And i have tuned my truck with the CALC.VE tutorial, with the check engine light on with these two codes, P0420 and P0430, which are saying my cats aren't working, when i don't have cats. How can one tune the truck to allow any rate acceptable from the rear o2 sensors, so it basically only uses the front two o2 sensors?

P.S. I also have two LC-1's to put on my truck(true dual exhaust with long tube headers) will i need to re activate the rear two o2 sensors and use their readings?

On a side note, my truck has a variable idle, it idle's high, and then idle's low, could this be from the knock sensors? I had a code come up a little while ago saying my knock sensors, so i bought new knock sensors and intake gasket, and then the code went away.

Edit:
Another thing, i have an electric fan kit, dual fan, variable speed, temperature switch and all the wiring, i was wondering if there was any tuning i could do when i put it on to get better results from the kit.

[Gregs]

Easy, all you need to do is go under engine diagnostics and disable those codes. Also you can turn all your cat protection fueling off if you havent done so yet. As far as knock sensors, I personally would just do the job if I had the parts laying around.

[ippielb]

Yup, i've deactivated cat protection fueling, and i've just turned off the codes. I am planning on doing the knock sensors still when i get the time to, i'm harvesting right now, so i don't have the time to rip into my truck at the moment. Would knock sensors cause the random idle? Going from high octane table to the low table?

Thanks

[Gregs]

sounds like it. i mean if they're showing kr at idle because there messed up then yeah it would throw itself down to low octane table for sure.

just curious about your exhaust setup, do you have an x or h pipe in there?

[ippielb]

NO X pipe or H pipe, true dual all the way through.

I just need to find where i put that intake gasket now then i'll swap the new sensors in this weekend hopefully.

[Gregs]

Is it just personal preferance that you did "true duals" cause an x or h pipe will sure help your engine performance wise?

did you see the how-to out there about making a dam of rtv around the knock sensors before you put it all back together?

[ippielb]

It was personal preference. I like the sound of a true dual set up. And yes I've done a few knock sensors on these trucks. I posted up some pictures in the knock sensor thread wen changing them.

[Gregs]

It was personal preference. I like the sound of a true dual set up. And yes I've done a few knock sensors on these trucks. I posted up some pictures in the knock sensor thread wen changing them.

10-4, hope this fixes your problem

[ippielb]

One question, with an H pipe, what benefits would it give? And just my luck, now i can't find the intake gasket...

[Gregs]

One question, with an H pipe, what benefits would it give? And just my luck, now i can't find the intake gasket...

both the h and the x pipe equalize exhaust pressures, i the h pipe is supposed to give more low end torque, where as the x pipe is supposed to give more upper rpm power. From the research i have done there is debate about whether there really is a noticeable difference between the two designs. In the end as long as you have one or the other they both work. i personally have a x pipe because its a cleaned install than the h pipe.

[06redram]

The sound is much better with the X-pipe