PO421:Warm Up Catalyst-below threshold (bank #1) CEL
#35
Hello everyone i need some serious help with this.
My cel light came on recently so i took it to advance autoparts and they told me it's the o2 sensor bank 1 p035 was the code so i changed it then it came on again with a code of p0421 which then said warm up catalyst bank 2. i then took it to mitsubishi & they put it on their computer & told me that i'd have to pay 1425.00 to replace the exhaust manifold that comes with the cat! Well, I don't have that kind of money. I asked him what would happen if i just changed the cat & he said it could work. So i called many muffler places to see if they have a specific cat for it they said no. When i purchased my magnaflow exhaust back in 05 they gave me a free cat with it. so I put that 1. now it threw the cel light again advance told me
that it's warm up catalyst bank 1. what should i do? HELP PLEASE!!!!! I was thinking to put headers from roadracemotorsports they have a cel iliminator that comes with it, please advise.
My cel light came on recently so i took it to advance autoparts and they told me it's the o2 sensor bank 1 p035 was the code so i changed it then it came on again with a code of p0421 which then said warm up catalyst bank 2. i then took it to mitsubishi & they put it on their computer & told me that i'd have to pay 1425.00 to replace the exhaust manifold that comes with the cat! Well, I don't have that kind of money. I asked him what would happen if i just changed the cat & he said it could work. So i called many muffler places to see if they have a specific cat for it they said no. When i purchased my magnaflow exhaust back in 05 they gave me a free cat with it. so I put that 1. now it threw the cel light again advance told me
that it's warm up catalyst bank 1. what should i do? HELP PLEASE!!!!! I was thinking to put headers from roadracemotorsports they have a cel iliminator that comes with it, please advise.
#36
went for a smog check for my 02 ES and got code P0421 & P0171 because of my MIL (service engine soon) being on. of course i failed the smog check because of the MIL lamp being on. i called the local shop and they were going to charge me like $500.
i called the delearship and told service that i got these 2 codes when i went for a smog check. he took down my VIN and he said that there was a recall on the CAT. i have over 130K miles on my car. i brought it down to the dealership, they fixed it (according to the paper work they actually replaced the cat). and there were 2 recalls on my car. the other was a cooling fan controller. both have been fixed/repaired for free of course.
the P0421 was the cat and it was affecting the P0171 to come on.
i re-smogged and i passed.
you should call your dealership and let them know there is a recall on your car and they'll repair/replace it for free.
this is the actual description of the work done on my car printed by mitsu
CODE: C0409ZXX
Type W4
Cooling Fan Controller Recall
CODE C0505JXX
Type W4 Catalytic converter - emission recall
i called the delearship and told service that i got these 2 codes when i went for a smog check. he took down my VIN and he said that there was a recall on the CAT. i have over 130K miles on my car. i brought it down to the dealership, they fixed it (according to the paper work they actually replaced the cat). and there were 2 recalls on my car. the other was a cooling fan controller. both have been fixed/repaired for free of course.
the P0421 was the cat and it was affecting the P0171 to come on.
i re-smogged and i passed.
you should call your dealership and let them know there is a recall on your car and they'll repair/replace it for free.
this is the actual description of the work done on my car printed by mitsu
CODE: C0409ZXX
Type W4
Cooling Fan Controller Recall
CODE C0505JXX
Type W4 Catalytic converter - emission recall
#38
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hey guys sorry for bumping such an old thread, but just trying to clarify. I have the P421 code going off and on periodically. I just have stock exhaust(no headers) would this CEL eliminator fix my problem or should i look into checking the internal integrity of the cat first, as alldata said it may be a deteriorated cat.
#39
Evolved Member
iTrader: (14)
hey guys sorry for bumping such an old thread, but just trying to clarify. I have the P421 code going off and on periodically. I just have stock exhaust(no headers) would this CEL eliminator fix my problem or should i look into checking the internal integrity of the cat first, as alldata said it may be a deteriorated cat.
Last edited by 03lances; Dec 4, 2011 at 12:36 AM.
#41
Evolved Member
iTrader: (2)
My money is on the bad cat. How many miles are on your car? No matter what, 100k mi or less you can get that replaced for free. I bought my car as a repo from a bank, paid $700 for it and once I got it back on the road I had this code. I took it to the dealership and they flashed the ecu, that helped for like a week then it came back. So I took it back and they replaced the cat free of charge, $1000 job according to the dealership, doesnt matter to me since it was free and the code has not returned since and its been like 4 years. You can take it to any exhaust shop if your over the mileage and shouldn't be more than like $200-300.
my oz has lil bit over 78k on the odo, built in aug 02, bought it in 2007 and im second owner... i get the p0421 on and off
Last edited by OZR_Lancer; Dec 4, 2011 at 08:41 PM.
#42
Evolved Member
iTrader: (14)
http://www.epa.gov/oms/consumer/warr95fs.txt
I swear I was told 100k by a Mitsu dealership so you may want to call and see. In your case however with it going on and off they may not cover it either way. Mine was a steady CEL and at the time the car was only 4 or 5 years old and at about 65k.
#43
Evolving Member
I have been getting the P0421 for quite awhile now and I know I need to replace the catalytic converter on mine. I had it taken to a shop and they checked out all the sensors and they did indeed confirm that it's the 02 sensor. After 211,500 miles, who is really surprised.
Unfortunately, I cannot afford to replace the catalytic converter at this time as the one from the dealer is about $800 installed. Sometimes I just want do a cat delete, but I don't that can really be done and still have the ability to pass emissions. Plus I want to be able to comply, even though it's basically sticking a potato in the works.
It's severely affected my mileage as well. Granted I did change my plugs over about 21,500 miles ago, I was getting about 32 MPG and this was in the summer. But this is getting ridiculous. I'm getting 27 MPG / 290 miles before the idiot light comes on. That's using about 10.500 gallons on average per fill up.
Do any of you think that when I replace the front catalytic converter that my mileage should logically go up? Help me out on this.
Unfortunately, I cannot afford to replace the catalytic converter at this time as the one from the dealer is about $800 installed. Sometimes I just want do a cat delete, but I don't that can really be done and still have the ability to pass emissions. Plus I want to be able to comply, even though it's basically sticking a potato in the works.
It's severely affected my mileage as well. Granted I did change my plugs over about 21,500 miles ago, I was getting about 32 MPG and this was in the summer. But this is getting ridiculous. I'm getting 27 MPG / 290 miles before the idiot light comes on. That's using about 10.500 gallons on average per fill up.
Do any of you think that when I replace the front catalytic converter that my mileage should logically go up? Help me out on this.
#45
I have had this code for years, I've changed o2 sensers, and didn't fix it. I think I'm gonna get the magna flow high flow cat from RRM to see if it works, but with this code is it the first or second cat? If it's the second cat it should work right?