 Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2
 ·RoadRunner Cable
3 edits | catalytic converter? P0420 getting a new issue
catalytic converter code P0420
P0420 Catalyst System Efficiency Below Threshold (bank1)
I think the o2 sensor needs replacement because of the fuel regulator issue ,cause it to get "dirty" due to the rich mixture.
Not worried about passing smog since that is 9 months away
I had it reset to see if it comes back on maybe just a fluke.
Not getting any smoke out of the rear end tail pipe.
Please no tree hugger crap in this thread . |
|
|
|
jsouthJsouth
join:2000-12-12
Wichita, KS | Re: catalytic converter? P0240 Could be.I wouldhavea shop place it on a scanner to narrow it down. My code turned out to be a bad egr valve. |
|
 mattmagPremium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3
1 edit | reply to Anonymous_
99% of the time, a P0420 means you need to replace the deficient converter. O2 sensor failure *will not* cause the P0420 to set, but rather will give sensor failure codes. Monitoring the catalyst efficiency requires both the upstream and downstream sensors to be properly operating, so it is generally a very accurate failure code.
Nothing wrong with clearing it and seeing if it comes back, that's prudent.
EDIT: Dyslexia.....lol |
|
 cdruGo ColtsPremium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7 | reply to Anonymous_
Is the error P0240, or P0420? Catalyst system efficiency below threshold is P0420 although it seems that dyslexia on the internet is very common and they get flipped.
I'd visually inspect things to make sure that there isn't any damage to the O2 wiring harness, make sure the plug(s) are tight, etc as well as make sure there aren't any exhaust leaks, reset the code, and go from there. |
|
mattmagPremium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3 | That's funny, because the first reply I typed "P0420" then realized it didn't match his post and changed it. Guess my subliminal memory should have been obeyed.  |
|
 Gordo74Premium
join:2003-10-28
Monroeville, PA | reply to Anonymous_
P0420 on my Impala ended up being that there was a vacuum leak in the system near the gas tank. A tube came loose is all. |
|
 TA63ST215WPremium,MVM
join:2000-11-23
there
kudos:2
 ·TekSavvy DSL
·Cogeco Cable
| reply to Gordo74
Re: catalytic converter? P0240 said by Gordo74:P0420 on my Impala ended up being that there was a vacuum leak in the system near the gas tank. A tube came loose is all.
That makes no sense. Perhaps you have misremembered your code?
--
The talented hawk speaks French. |
|
Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2 Reviews:
·RoadRunner Cable
| yeah it was p0420 got it rechecked had two entries on it. going to change out the sensor first to see if it fixes that. Since it's way cheaper then paying $1200 to replace it with a factory catalytic converter
New state law requires factory down to the exact model and production code. Other wise automatic fail.
If it was the catalytic converter I would be getting more codes besides the P0420
CEL was tripped when behind a diesel bus that was pouring out smoke.. assuming it was sucking craptastic air from the truck which caused it to trip .
and caused higher emissions from the car = CEL |
|
mattmagPremium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3 | said by Anonymous_:If it was the catalytic converter I would be getting more codes besides the P0420
What makes you think that? Your assumption in this case is wrong. P0420 is very often a stand-alone code, and requires no other associated failures to enable it. |
|
Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2 | I was behind a bus that was pouring out a lot of smoke, when the CEL came on. |
|
mattmagPremium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3
1 edit | said by Anonymous_:I was behind a bus that was pouring out a lot of smoke, when the CEL came on.
You were behind a smoking bus *twice* to make it come on? You said you already had the code cleared once. And, that's a virtually impossible scenario to cause that code anyway.
What sensor do you plan on replacing on a blind guess? Upstream or downstream? I really don't understand why people want to come up with every reason under the sun why this code sets. There is a converter failure code so you want to replace the oxygen sensor. If a code sets for an cylinder #4 misfire, are you going to replace a headlamp?
I'm being straight here--- BOTH related-bank oxygen sensors MUST BE operating properly for this failure code to occur. The computer is measuring exhaust oxygen content BOTH before AND after the catalyst to determine its efficiency. A malfunctioning O2 sensor strictly prevents this diagnostic cycle from running, and will set a SENSOR failure code, NOT a catalyst code. There are no "false positives" here.
I will add that the best course of repair is proper diagnosis. Get the system tested, preferably by a shop that can scope the components to get the correct picture. Like I said, very high percentage its the converter. Oxygen sensor failure is very rare. |
|
Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2 Reviews:
·RoadRunner Cable
| said by mattmag:said by Anonymous_:I was behind a bus that was pouring out a lot of smoke, when the CEL came on.
You were behind a smoking bus *twice* to make it come on? You said you already had the code cleared once. And, that's a virtually impossible scenario to cause that code anyway. What sensor do you plan on replacing on a blind guess? Upstream or downstream? I really don't understand why people want to come up with every reason under the sun why this code sets. There is a converter failure code so you want to replace the oxygen sensor. If a code sets for an cylinder #4 misfire, are you going to replace a headlamp? I'm being straight here--- BOTH related-bank oxygen sensors MUST BE operating properly for this failure code to occur. The computer is measuring exhaust oxygen content BOTH before AND after the catalyst to determine its efficiency. A malfunctioning O2 sensor strictly prevents this diagnostic cycle from running, and will set a SENSOR failure code, NOT a catalyst code. There are no "false positives" here. I will add that the best course of repair is proper diagnosis. Get the system tested, preferably by a shop that can scope the components to get the correct picture. Like I said, very high percentage its the converter. Oxygen sensor failure is very rare. I'll just wait tell I need to do the smog test (you bet I going to clear the code before I get the test done)
if it passes then it's a faulty SENSOR. if it fails I get it fixed
--
Well, does your car at least turn into something else? Sometimes I turn it into a trashcan. Hmm... |
|
bgraham
join:2001-03-15
Smithtown, NY Reviews:
 ·VOIPo
·Verizon VoiceWing
| reply to Anonymous_
Re: catalytic converter? P0420 The OP would be wise to listen to the advice of mattmag. I too decided against paying $1200 for the OEM Buick cat and went to Rockauto and paid $200. Exactly a week after the 12 mos warranty expired I started getting a PO420 about every other week. Googled the problem and there is a lot of issues with PO420 and cheap replacement cats. Replacing the cat is the only answer.
I will add that I replaced the original OEM cat at 100k miles due to it being blocked. |
|
| reply to Anonymous_
said by Anonymous_:getting a new issue
catalytic converter code P0420
P0420 Catalyst System Efficiency Below Threshold (bank1)
I think the o2 sensor needs replacement because of the fuel regulator issue ,cause it to get "dirty" due to the rich mixture.
Not worried about passing smog since that is 9 months away
I had it reset to see if it comes back on maybe just a fluke.
Not getting any smoke out of the rear end tail pipe.
Please no tree hugger crap in this thread .
i bought a 02 grand prix with a hollowed out cat and it was throwing this code, my 97 grand prix also threw it. replacing the cat fixed it. |
|
| reply to mattmag
Re: catalytic converter? P0240 said by mattmag:said by Anonymous_:If it was the catalytic converter I would be getting more codes besides the P0420
What makes you think that? Your assumption in this case is wrong. P0420 is very often a stand-alone code, and requires no other associated failures to enable it. exactly, like i just posted, faulty cats threw that code on my both grand prix. same car as the impala, and those were the only codes i had |
|
 rockotman...Blown On The Steel BreezeEmerging Research
join:2000-08-06
DSotM
kudos:2 | reply to Anonymous_
Re: catalytic converter? P0420 I have had a P0420 code once. It was indeed a failed converter. Luckily, the converter was still under warranty.
--
Shine on you crazy diamond... |
|
Anonymous_AnonymousPremium
join:2004-06-21
127.0.0.1
kudos:2 Reviews:
·RoadRunner Cable
| going to get it fixed but later this year when it's time to smog.
FACTORY replacement is required to pass.
otherwise getting a after market is throwing money into a money pit.
--
Well, does your car at least turn into something else? Sometimes I turn it into a trashcan. Hmm... |
|
rockotman...Blown On The Steel BreezeEmerging Research
join:2000-08-06
DSotM
kudos:2 | How many miles on the car? By federal law, cats are required to be covered for 8 years/80K miles on cars from 1995 and later.
--
Shine on you crazy diamond... |
|
| reply to Anonymous_
said by Anonymous_:I think the o2 sensor needs replacement because of the fuel regulator issue ,cause it to get "dirty" due to the rich mixture.
I've heard that rich mixtures will cause cats to overheat and kill them. |
|
