Check Engine light - code P0420

question, but can the replacement of the cat. converter cause a drop
> in the mileage too (i.e. if I have a bad cat.) ?

It doesn't have to be defective to cause a mileage drop. It could simply be
a poorer design that restricts exhaust flow more than the OEM cat.

This is one of the items that I'd stick with OEM unless I had proof the
replacement would be better.

i use alot of after market replacement converters with no issues
i just make sure it is for the correct app.
i have also found on some asian cars the idle is set to a higher mark at start up
so the pre cats get heated up as fast as possible. to get a more accurate 02
readings
i have replaced a few iac's that wasn't reaching target idle specs resulting in
cat eff. codes



Steve Austin wrote:

> Noozer wrote:
> > question, but can the replacement of the cat. converter cause a drop
> >> in the mileage too (i.e. if I have a bad cat.) ?
> >
> > It doesn't have to be defective to cause a mileage drop. It could simply be
> > a poorer design that restricts exhaust flow more than the OEM cat.
> >
> > This is one of the items that I'd stick with OEM unless I had proof the
> > replacement would be better.
> >
> >
> Replacements are almost never better.

..
<<INLINE>>
======
======
aarcuda69062 > wrote:
..
It's not surprising that you wouldn't know this. <snicker>
..
~~who said.........i didn't know ? !! ?? <chuckle,chuckle>~~
..
..
..

The answer to the first part is; the atmosphere (duh), which is
usually around 21% oxygen but it varies depending on how much
dope *you're* smoking in proximity.
..
~~so......what's the atmosphere like INSIDE a 2000 degree
cat that's been running down the road for over an hour?
<chuckle,chuckle>~~
..
..
..

You know, that air fuel ratio thing.
The answer to the second part is; the Cerium wash coat.
Like I said, you need some classes because this stuff is (well)
over a decade old.

..
~~yep......and so am I....and tell me.......how MANY googles
does it take to git to the center of a tootsie pop?
<lmao>~~

On Dec 4, 8:27 pm, aarcuda69062 > wrote:
> In article
> >,
>
> Marsh Monster > wrote:
>
> > =======
> > =======
> > On Dec 4, 5:54 pm, Mark >
> > So if I reset the code and it comes back, then it is not due to fuel
> > injection cleaning? I could use this approach to eliminate this
> > service and the it would point to maybe a damaged converter?
>
> > =========
> > =========
>
> > What IF....that cleaning busted loose enough crap THROUGHOUT the
> > system and SOME this CRAP is now BAKED on yer sensor/sensors??
>
> How about; there would be O2 sensor performance codes setting
> instead of cat efficiency codes. <sheesh>
>
>
>
> > but......
>
> > you do what you want........
>
> > I'VE DONE TOLD YER DUMBASS TO CARRY IT TO THE FLUSH DUDE
> > AND GIT IT LOOKED AT FOR FK'N FREE!!!!!!!!!!!
>
> Because even though there are thousands of fuel injector flush
> services done every day, there is yet no industry wide problem
> with those services causing catalytic convertor failures in spite
> of the fact that aftermarket convertors are known to be less than
> 50% efficient (which is no where near good enough) right out of
> the box?
>
> > but........
>
> > clear the codes if you want.....
> > then....if the codes comeback......
> > go blame the dude that put the convertor on.....
>
> For trying the cheap way out.
>
> > jest do this when you do......
>
> > make sure you tell HIM.....that system was flushed AFTER
> > the convertor was put on.........i mean........
>
> Do these convertors come with a warning that injector flushing is
> not allowed and/or will void any warranty?
> (feel free to post a copy)
>
> > we do wanna be HONEST here .......rite??
>
> Why, you're not.
>
> >
>
> > ~:~
> > MarshMonster
> > ~takes a toke.......wonders if anyone here has been smart enough
> > to google this subjest.........takes a toke......lhao~
>
> Some of us don't need to because we actually do it every day for
> a living.
>
> So Mr. Doobie, how many times a day do you use Google to repair
> your customers vehicles?

==========
==========

NEVER.......I use MOD........




~:~
marsh
~sips his crownroyal~
~:~

On Dec 5, 7:02 pm, Mark > wrote:
> Thanks everyone for your insights, suggestions and advice. This forum
> offers a lot of expert advice from different people with different
> point of views and experiences, and thats what makes it so valuable. I
> appreciate everyone taking their precious time to respond.
>
> I just wanted to post an update that my check engine light went away
> this evening. I did not do anything yet. I went to work in the morning
> and the light was on. When returning from work, I turned on the car
> and the light was gone. I have made a couple of short trips since then
> and the light has not come back on. Based on this occurence, I would
> again have to lean on the experts here to understand what this means,
> and if it may have temporarily disappeared and could return again.
>
> Another problem that I didn't bring up earlier, as I did not want to
> divert attention from the CEL problem, was that my fuel mileage had
> dropped since I had replaced the catalytic converter. Previously I
> would get about 24mpg and after replacing the converter I am getting
> around 20mpg. I noticed the drop in mileage after replacing the cat
> and before the fuel injection service. I have to ask this dumb
> question, but can the replacement of the cat. converter cause a drop
> in the mileage too (i.e. if I have a bad cat.) ?
>
> Thanks everyone for your help.

============
============

As to yer 1st two paragraphs........that's bout the nicest way
ANYONE has ever told me to fk off.




and.........YES.......the cat may cause the drop.


oh........and........YOU'RE FREEK'N FLUSH CAUSED THE
LIGHT TO COME ON.




ok.......so i said it again.......i feel better again.



~:~
marsh
~sips his crownroyal......takes a toke.....farts a big one........
ooooch...........backpreasure~~
~:~

=======
=======
philthy > wrote:
i use alot of after market replacement converters with no issues
i just make sure it is for the correct app.

=======
=======

The universal ones cause the most issues.......the OP
has yet to say what he PAID for the cat...which would be
a GOOD indicator of whether the one installed on his vehicle
was a Direct Fit replacement or.....a universal cat....which, price
alone isn't a gaurantee that a Direct Fit was used...some, alot,
many.....muffler shops......install universals and CHARGE for
Direct Fit. FACT, not fiction.


anywhoooooo..........

did i ever mention the time i worked for.......
CATCO ???


no......oh......ok.






~:~
marsh
~takes a toke.......mmmmmm.......gooooood stuff~
~:~

In article

m>,
Marsh Monster > wrote:

> .
> <<INLINE>>
> ======
> ======
> aarcuda69062 > wrote:
> .
> It's not surprising that you wouldn't know this. <snicker>
> .
> ~~who said.........i didn't know ? !! ?? <chuckle,chuckle>~~

You did in numerous ways.

> .
> .
>
> The answer to the first part is; the atmosphere (duh), which is
> usually around 21% oxygen but it varies depending on how much
> dope *you're* smoking in proximity.
> .
> ~~so......what's the atmosphere like INSIDE a 2000 degree
> cat that's been running down the road for over an hour?
> <chuckle,chuckle>~~

Well, <chuckle, chuckle> i would best describe it as
'problematic' since the normal operating temperature of a
catalytic convertor in a properly functioning system is no where
NEAR 2000 degrees.
Once again, buzz words and cliches fail you.

> .
> .
>
> You know, that air fuel ratio thing.
> The answer to the second part is; the Cerium wash coat.
> Like I said, you need some classes because this stuff is (well)
> over a decade old.
>
> .
> ~~yep......and so am I....and tell me.......how MANY googles
> does it take to git to the center of a tootsie pop?
> <lmao>~~

You're probably the only one here that can answer that...

> .
> .
> This has nothing to do with whether or not I am smarter than the
> OE engineers. Oxygen sensors DO NOT react to raw fuel as you
> implied in your post, the post cat O2 will not set a efficiency
> code just because an engine is/was over fueled as your post
> implied.
> .
> ~~well.....you PROVED with yer count to 3 and ck the spark
> post.....that you're nowhere near as smart as the engineers.....

I made a math mistake and owned up to it.
That hardly makes me wrong about everything else, unless of
course I'm dealing with someone in a desperate situation.

> so........we'll jest let that one drop.

I doubt you would.

> HOWEVER....<chuckle>...
> I DID NOT, never, once,ever,nope.....IMPLY...the code was set
> ""because an engine is/was over fueled""...................
> nope...didn't. <<chuckle..giggle..toke...>>~~
> .
> ~~go back...ck what i wrote..not what you read....
> <<giggle..toke...sip...chukle...highashellnow>>~ ~

Okay:
In article

m>,
Marsh Monster > wrote:

" the Fuel System service caused the light to come on........."

"the Fuel mixture is now rich..."

" the injectors were cleaned and now one or more is NOT sealing ."

There's the article number and your statements.
So, you're either a liar or too stoned to remember what you wrote.
Either way, you're worthless.

> .
> .
>
> Speaking of other posts, do you want to take another shot at
> spelling 'definitely'?
> (hint; there is no "a")
> .
> ~~cool...........thanks........now there's some info i kin use~~

Indeed!

>
>
> .
> .
> .
>
> Well, you posted on Sunday and mentioned that you were watching
> the "4 gass" while fiddling with the throttle body.
> So, the real case here is; you felt need for a clever buzz word
> to lend some credibility to your asinine statements.
> .
> ~~I NEVER !!!!...........fact not fiction, again...go back...
> reed whut i writ not whut you red...<toke..chukle>~

On Sunday December 2, In article

m>,
Marsh Monster > wrote:
~:~
marsh
~takes a toke......watch's the readings on the 4gas as he
cleans the throttlebody~

Again, either way, you're a liar, and a fool for using a 4 gas
while cleaning a throttle body.

> .
> .
>
> So, tell me about your "4 gass", what brand is it? Is it a
> non-dispersive infra red or flame ionization bench?
> Does it have constant volume sampling? Does it allow for
> corrected NOx sampling?
> .
> ~~It's hooked to a $10,000 Allen scope......

Allen went tits up what, 15 years ago?
An antique.
AND, you haven't answered the rest of the question.
('cuz you have no clue)

> whut's yers hooked to?

A $4000 Panasonic Toughbook, which sits on a shelf below a
$12,000 Snap-On scope which is two drawers above a Sun LS 2000
labscope which is in the drawer above the drawer which holds
$20,000 worth of scan tools, OEM and aftermarket.

In article

m>,
Marsh Monster > wrote:

> > So Mr. Doobie, how many times a day do you use Google to repair
> > your customers vehicles?
>
> ==========
> ==========
>
> NEVER.......I use MOD........

Really?

Where in Mitchell do they instruct tying knots in brake lines?
Where in Mitchell do they describe making a bubble flare by using
a double flaring tool?

In article

m>,
Marsh Monster > wrote:

> did i ever mention the time i worked for.......
> CATCO ???

No, but so what? They make crap.

On Dec 5, 8:02 pm, Mark > wrote:
> I just wanted to post an update that my check engine light went away
> this evening. I did not do anything yet. I went to work in the morning
> and the light was on. When returning from work, I turned on the car
> and the light was gone. I have made a couple of short trips since then
> and the light has not come back on. Based on this occurence, I would
> again have to lean on the experts here to understand what this means,
> and if it may have temporarily disappeared and could return again.
>
> Another problem that I didn't bring up earlier, as I did not want to
> divert attention from the CEL problem, was that my fuel mileage had
> dropped since I had replaced the catalytic converter. Previously I
> would get about 24mpg and after replacing the converter I am getting
> around 20mpg. I noticed the drop in mileage after replacing the cat
> and before the fuel injection service. I have to ask this dumb
> question, but can the replacement of the cat. converter cause a drop
> in the mileage too (i.e. if I have a bad cat.) ?
>
> Thanks everyone for your help.

My check engine light came back on. So in a matter of the past 2
weeks, the light came on, then went off and came back on. Someone had
mentioned earlier in this post to reset the light and see if it comes
back on, which it did without me manually resetting it.

Also someone asked about how much I paid. I paid $250 for the flex
pipe + converter, and yes, this is most likely a universal converter
and not a direct fit as the mechanic had to weld it in.

I did take my car back to the mechanic (the light was off that time),
he inspected and did not find any leaks. He still welded it again just
to close any minor leaks that may be present. The light came back on a
couple of days later, so don't think the second round of welding did
any good. Other than this, he does not see anything wrong in 'his'
converter.

What are my options at this point? Do I have to now go and buy a new
OEM converter?