Check engine light

[19ClearCobra96]

I am getting codes of p0420, and p0430 after I installed LT headers and off-road Hpipe. Is that normal? What can I do to get rid of it? 96 cobra

 

[Yellow98SVT]

P0420
Catalyst System Efficiency Below Limit, Bank No. 1

P0421
Catalyst System Efficiency Below Limit, Bank No. 1

P0430
Catalyst System Efficiency Below Limit, Bank No. 2

P0431
Catalyst System Efficiency Below Limit, Bank No. 2

Some kinda problem with your Cats, or, lack of them. Someone will chime in and say exactly what it is tho.

 

[slow98svt]

Do you have Mil Eliminators????

 

[SnakeBite98]

your computer is just unhappy because you have no cats, get the mils, and if you have dallas mustang ones right now, get different ones.

 

[slow98svt]

I got my Mils from Ninosport and they have been working on my GT for over a year with no problems

 

[SnakeBite98]

yea, dallas mustang's stuff sucks, for me at least. i have the mils and speedcal from them and they both are intermittent.

 

[19ClearCobra96]

yeah i got mils, they go on the rear ones right. I got them froma guy on this board

 

[SnakeBite98]

yea they go on the rear. i would go clear the code and then just see if it comes back, maybe they're just intermittent like mine.

 

[19ClearCobra96]

well it changed now to code 136

 

[SnakeBite98]

your computer know thinks that your o2's are bad

 

[Yellow98SVT]

Downstream HO2S Circuit Fault, Bank No. 1


???? Someone, anyone?