Modded Mustang Forums banner

1 - 10 of 10 Posts

·
Banned
Joined
·
8,398 Posts
Discussion Starter #1
catalyst system efficiency below threshold bank 1

cylinder 1 misfire detected

recently changed plugs wires and coil pack, about a week ago, both codes came on today, cleared the codes and drove 4 miles, they didn't come back.

fluke?
 

·
Registered
Joined
·
3,702 Posts
If they dont come back on, it was a fluke.

Make sure to double check that your wires are on in the right order
 

·
Registered
Joined
·
730 Posts
yeah make sure everything is tight and that your spark plugs were gapped correctly...

also give it more like 40 miles and if it doesnt come back on then your fine.....

its just a waiting game haha im in the same boat... waiting to see if my CEL is going to come back on

i swear after all the trouble ( and im sure you too ) if that damn light comes back on im gonna :shitbrick
 

·
I'm doing it wrong
Joined
·
5,495 Posts
P0420 is usually one of 3 things that I have noticed.

Either bad o2's on whichever side is causing the code. It could be a bad cat, or possibly a leak right around the cat. I'd check there first.
 

·
Banned
Joined
·
8,398 Posts
Discussion Starter #5
im pretty pissed..

the cel isn't back yet, i got my exhaust done,

but lets just say it was a high revving drive on the way home, and my car seemed to get a little slower and slower, and then it started to kind of spit and sputter, i started to smell something, cant quite say what it was. and i was getting a ton of popping coming out the rear, my acceleration was weak, i dont think its the exhaust, i went with 2.5" piping which is a little big but other people have done it on the same setup.

im guessing that after all the driving i did on my cats when my coilpack was ruined, with all the misfires and high revving low throttle response, i clogged a cat? i guess that'd make sense why one of the codes came on?...
 

·
Registered
Joined
·
730 Posts
im pretty pissed..

the cel isn't back yet, i got my exhaust done,

but lets just say it was a high revving drive on the way home, and my car seemed to get a little slower and slower, and then it started to kind of spit and sputter, i started to smell something, cant quite say what it was. and i was getting a ton of popping coming out the rear, my acceleration was weak, i dont think its the exhaust, i went with 2.5" piping which is a little big but other people have done it on the same setup.

im guessing that after all the driving i did on my cats when my coilpack was ruined, with all the misfires and high revving low throttle response, i clogged a cat? i guess that'd make sense why one of the codes came on?...
yes a rotten egg smell is a #1 symptom of a bad catalytic converter (or any funny smell for that)

with those symptoms i would say you need to either get a midpipe and run an offroad set up or replace the cat and you will be fine.

you could also hollow it out and weld it back in

but seriously driving on a converter in that bad of condition is a NO NO!

get an x or and h pipe and sell the converters to make more than half your money back.

also you can make some mil eliminators for like 5 bucks so u can run the offroad setup it not hard.
 

·
Banned
Joined
·
8,398 Posts
Discussion Starter #7
pretty sure its a clogged cat, definitely getting the weird smell, car won't do much under load, couldn't break past 65 mph today.

what would you do if you were in this situation?
 

·
Banned
Joined
·
8,398 Posts
Discussion Starter #8
Drove the car home, about 20 miles, went decently, but never pushed it above 2k rpm, reached 75 mph and didnt push it past that

tried to get my car inspected to pass emissions->rejected->cats and something else weren't ready for inspection... i guess its cause i put my tune on yesterday.

I left my car idling when i got home after the 20 mile drive, I put my hand up to the left tip, and the exhaust came out in waves like, cough cough cough whereas on the passenger side it was a solid flow, like a soft-medium exhale...

cat 1 is the passenger side, so im guessing its like that because that cat must be clogged from the misfiring problems i had after my coilpack bullshit, the exhaust coming out of the right side is not loud at all, much quieter than the left.

right now i've basically got two solutions...

slp high flow cats, cut out old cats, get these welded in

longtubes w/catted h pipe? (will this pass va emissions?) my emission testing was due this month..

open/in need of help/suggestions
 
1 - 10 of 10 Posts
Top