p0420 question
#11
Member
Posts like a V-Tak
Thread Starter
Join Date: Aug 2009
Location: Forth Worth, Texas
Posts: 79
Likes: 0
Received 0 Likes
on
0 Posts
I replaced the vacum line again it had pretty much melted to the alternator ran it away far enough from the alternator and */c so i wont have that problem again I listened to the cat it has a slight raddle so more then likey the cat has gone out again
#12
Senior Member
Certified GM nut
DTC P0420, "Catalyst System Efficiency Below Threshold" means that your catalytic converter is doing a poor job of breaking down the ozone-depleting and smog-generating molecules in your exhaust. Thus, you won't pass your state'* emissions testing while this code is set.
Rarely, it can mean that your downstream (post-cat) O2 sensor has gotten tired, but since you've replaced both, that rules that out.
This is where we would normally suggest that you check for exhaust leaks, but if your cat is rattling, that'* a telltale sign that its internals are in pieces.
#16
Member
Posts like a V-Tak
Thread Starter
Join Date: Aug 2009
Location: Forth Worth, Texas
Posts: 79
Likes: 0
Received 0 Likes
on
0 Posts
they said they did but so i un hooked the battey for 30 mins pulled the pcm fuses and let it sit it hasnt come back on i just cant get the evap ready its self so i can get inspected
#17
Senior Member
True Car Nut
if thats the only code, it may pass anyway, after 2000 is one code not ready still passes in ny. maybe the same for you.
before 2000 you can have two here
before 2000 you can have two here
#19
If the system has been over-fueling because of a vacuum leak over a long period of time, the catalyst is working harder to burn unnecessary raw fuel coming down the line and could prematurely fail.
Thread
Thread Starter
Forum
Replies
Last Post