P0420 + P0420P Fault Codes Catalyst Efficiency Below Threshhold (Bank

[aly]

my is 200 1999 is showing these two fault codes, (fink they both refer to the same thing) p0420 and p0420p not sure what the p stands for at the end of the 2nd code. anyone have any ideas? anyone know the most common reason for this? i know its refering to the cat but there is also a pre cat so im unsure which has the problem. :tsktsk:

[lenny123]

my is 200 1999 is showing these two fault codes, (fink they both refer to the same thing) p0420 and p0420p not sure what the p stands for at the end of the 2nd code. anyone have any ideas? anyone know the most common reason for this? i know its refering to the cat but there is also a pre cat so im unsure which has the problem. :tsktsk:

hi the p0420 is catalyst efficiency below threshold bank1 i had this code come up it turned out that the joint behind the rear cat before the last oxygen sensor was blowing from the joint so i put some new gaskets on and its not come back hope this helps .

[aly]

Thanks alot, i'll have a good look for any blows.