replaced cat converter and all three o2 sensor at same time. still get p0420 help

 

Did you actually diagnose the problem?

 

JUstr keep getting P0420 code even after reset(clearing)

 

Did you expect the act of clearing the code to fix the problem?? Since you seem to have missed the link I posted above I guess I'll repeat a step in that procedure... Are there any leaks in the system?

Have you considered that the replacement cat could be bad or inferior? Or that the replacement O2 sensors may not be reading properly?

Diagnosing vehicles is a lot more involved that just swapping out parts. Especially with the somewhat lack luster quality of aftermarket parts.

 

replaced with OEM parts. Quality sure not be an issue

 

Replaced plugs (platinum, MSD 8.5mm wires ,cap and rotor. Replace all three O2 sensors at same time. Cat only 6 months old. Still get P0420 codes.

 

I'll ask one last time... Did you run down through the diagnostic chart that I linked to previously? If so, what did you find?

 

I am new here. I have the P0420 code and the 98 blazer would bog or stutter when started sometimes but today it just strated and died and wont run anymore. I assume it is time to change the converter which is original....

I did read the sheet you ask everyone to go over and yes I do have collant leaking from the lower intake gasket.

What I want to know is how this affects the P0420 code... I have read a lo of threads and have not found this answer. So I am asking if the leak could cause the code? Doesnt seem like it but I thought I would ask for an explanation.

Thanks!

 

I doubt your LIM gasket leak is causing the catalyst efficiency code.

Actually using the diagnostic sheet goes far beyond reading it, but it's a start!

 

Woopt did you ever find out what was causing your P0420 after you changed your
Catalyst and O2 Sensors? A follow up would be appreciated. I have a similar problem.

Thanks Mark K