[FrenchCelt]

My check engine light popped on a few days ago and I got it to the Hyundai dealer today. The service guy told me the catalytic converter needs to be replaced and will cost $1,700...money I don't have and will not be able to save up by my next smog test. I live in California, so the part is likely very expensive. Anyone know where I can get the part as cheaply as possible so I can fix it myself? I saw somewhere that it's illegal to buy and install a used catalytic converter, so I guess I'll have to buy a new part.

 

[jsinton]

It might be your cat, but on the other hand I wouldn't be too quick to suspect that. Do you happen to know the trouble codes? Service guy should have written it on the ticket.

So is it a four or six cylinder?

 

[FrenchCelt]

The code is P0421. It's a 4 cylinder.

Edit: I Googled that code and learned that it could also be the O2 sensor or a bad spark plug...I wonder if they tested for those or went right for the higher cost repair hoping I wouldn't question it.

 

[jsinton]

Santa Fe with the four banger has a tendency to burn up the cat, seen it a couple of time. You won't know for sure until you remove the cat and look inside. I'd pull the spark plugs and look at them, just to be sure. If they were ok, then I'd pull off the cat and look inside. If that looks ok, I'd replace the O2 sensor.

 

[FrenchCelt]

I'm not qualified to make the call based on a visual inspection. I can do the work to remove and replace, but that's the extent of my skills. And it sounds like the catalytic converter is too expensive for me ($1,400 according to the dealer). I might just have to let it go and see if I can get financial assistance when I fail my smog test next time I renew my registration.

 

[jsinton]

It's actually easy to inspect. Of course, you know about plugs. You can just replace them for under $12 if you're not sure.

The cat is easy too. You just look inside for the catalyst material inside. If it's burnt, then it will be cracked and burnt with a big hole, or maybe completely disintegrated and laying around the bottom in pieces. If the material looks intact, then it's probably still good. In a worse case, you could post us a pic and we can tell you if it looks good or not.

Even the O2 sensor is do-able. You need a special O2 sensor socket to get it out, but that's the only hard part to replacement.... actually, that's not right.... you can remove that particular O2 sensor with a regular box end wrench, so it's even easier.

 

[FrenchCelt]

Ok, I'll give it a shot. Thanks for the input! :grin:

 

[cloud09]

Dont feel bad I live in California to and keep getting that code popped up once in a while when im driving far. I just hope its an O2 sensor but I heard that you can take the catalytic converter off and shine a flashlight in it on one side and look through the other side and if you cant or can barely see the light then your cat is pretty much plugged but if you can see the light really well then you know thats not the problem. I havent got around to do it but hoping its not plugged cause i as well dont have that kind of money to dish out on a new cat but i might just gut the sucker until i can find a used one. I know gutting is not the smartest thing to do and really wont help with CEL to go away but either way if its plugged its got to go and my performance is sluggish then normal so it could just be the cat.

 

[FrenchCelt]

So far I don't have any performance issues...the car runs just fine. Definitely needs a tune-up, though, including new plugs, which I'll do at 120,000 miles (I'm at 111,000 now). But it's pretty zippy and has good pickup, especially from a dead stop to freeway speed.

 

[lucky21]

QUOTE (FrenchCelt @ Sep 3 2010, 11:04 AM) index.php?act=findpost&pid=354035

So far I don't have any performance issues...the car runs just fine. Definitely needs a tune-up, though, including new plugs, which I'll do at 120,000 miles (I'm at 111,000 now). But it's pretty zippy and has good pickup, especially from a dead stop to freeway speed.

Hey! don't spend $1700 through your overpriced stealership!!!! If that cat is bad and you're ready to replace it grab a new one at www.hyundaioemparts.com or follow the link below which shows your cat.

www.hyundaioemparts.com .

This is a great website run by a dealer down in Florida which also sells on the internet. I'm a VW guy and there's one for us called 1stvwparts.com out near Seattle for my VW parts, but since I'm lucky enough to now service my GF's 2001 Santa Fe I'm now applying my VW tricks in finding good quality parts here in the Hyundai world!

I just called them right quick and verified that a cat for your 4 cyl 2003 SantaFe is 700 bucks. Since it's OEM and a genuine Hyunidai part you're good to pass all your CARB tests out there in your wacky state of CA. So if you take it out, post some pics, let one of us geeks determine if it's a bad cat or not, and then purchase and replace accordingly.

I'm not sure about the Hyundai codes, but I would def try to determine if it's an O2 sensor, those guys are easy, usually don't require the special tool, as Jsinton said and are notorious for crapping out around 100k miles. If you do need a "lambda" wrench (O2 sensors are known as Lambda sensors in dork world) usually they're rentable at a local parts store.

Worst case scenario you're staring at $700 instead of $1700 for a new cat... Good luck and Godspeed. Hopefully that helps a little bit.

PEACE! :57:
~Lucky

Sidenote: Just do your plugs now, if you've got one out to check, you might as well change them all. no need to get dirty 2x.

 

[jsinton]

He lives in California. He can't just buy any cat. Is your cat specifically for the California market?

 

[sbr711]

0421 catalyst efficiency below threshold... PCM logic has determined cat to be bum based on sensor activity.. you can look at the honeycomb all you want, but it is inputs from from S2 that tells PCM what is going on, and logic decides from there based on a lot of other inputs..

GDS in current data for ox sensors, tthen graph mode, and watch the sensors toggle...

Cat is $7-800 depending on dealer attitude, add for gaskets, 3 new not at bottom, think it is 2 bolt and 3 nut that hold cat to manifold... come to think of it, I have 1 in shed I can take pic of..... forgot to take it last week Saturday when I scrapped 9 cats for $420...

Here is what the cat looks like...

 

[snake52]

Thank you sbr711

for the pictures but dose the santafe 204 has two cats or just one what happen if the cat material just fall from the cat into the pipe and plugged how would i know

 

[sbr711]

Primary catalyst is in the pictures posted, pre-cat ox sensor in manifold for fuel trim, and post cat ox sensor (see threaded hole in lower cat just above the out flange to front pipe in the first picture) for cat efficiency monitor... The V6 has a second cat in the front pipe, it is not monitored, it is just the reduce emissions a bit more.

I think the 4 cylinder has a 2nd cat in the front pipe... I not pay a lot of attwntion to them,,, we just a V6 with exhaust leak in front pipe, it was approx $1200 for the pipe, add 2 gaskets, 4 nuts, and 2 bolts to install it in factory fashion.

 

[FrenchCelt]

QUOTE (lucky21 @ Sep 3 2010, 12:39 PM) index.php?act=findpost&pid=354106

Hey! don't spend $1700 through your overpriced stealership!!!! If that cat is bad and you're ready to replace it grab a new one at www.hyundaioemparts.com or follow the link below which shows your cat.

www.hyundaioemparts.com .

This is a great website run by a dealer down in Florida which also sells on the internet. I'm a VW guy and there's one for us called 1stvwparts.com out near Seattle for my VW parts, but since I'm lucky enough to now service my GF's 2001 Santa Fe I'm now applying my VW tricks in finding good quality parts here in the Hyundai world!

I just called them right quick and verified that a cat for your 4 cyl 2003 SantaFe is 700 bucks. Since it's OEM and a genuine Hyunidai part you're good to pass all your CARB tests out there in your wacky state of CA. So if you take it out, post some pics, let one of us geeks determine if it's a bad cat or not, and then purchase and replace accordingly.

I'm not sure about the Hyundai codes, but I would def try to determine if it's an O2 sensor, those guys are easy, usually don't require the special tool, as Jsinton said and are notorious for crapping out around 100k miles. If you do need a "lambda" wrench (O2 sensors are known as Lambda sensors in dork world) usually they're rentable at a local parts store.

Worst case scenario you're staring at $700 instead of $1700 for a new cat... Good luck and Godspeed. Hopefully that helps a little bit.

PEACE! :57:
~Lucky

Sidenote: Just do your plugs now, if you've got one out to check, you might as well change them all. no need to get dirty 2x.

Hmmm, if that cat is good for California, and I discover that's what must be replaced, then thanks for the tip! :thumbsup:

 

[Oxidation]

How do you get to the wires and connector on the downstream O2 sensor? It looks like it's buried pretty good on the 4cyl. Thanks for any help.

 

[sbr711]

QUOTE (Oxidation @ Jan 6 2011, 12:31 PM) index.php?act=findpost&pid=387377

How do you get to the wires and connector on the downstream O2 sensor? It looks like it's buried pretty good on the 4cyl. Thanks for any help.

Just follow the pigtail off sensor to the connector,, you got the new sensor in hand ? I think the connector is above bell housing all tangled in with some other stuff.. You need to move forward and access it and unplug it.

 

[Oxidation]

Thanks, Once you get it unplugged is the rest of the wire easy to pull out? Looks like a mess the way its routed.

You seem pretty knowlegable on the subject. I did hook a scanner up and watched the volts from the sensors and they did change when I stepped on the gas etc and both appear to be reading something. Does that indicate that the O2 sensor is OK? Do they start giving eroneous reading or do they usually just stop working?

Also, can I put an aftermarket cat in if I'm not in Calf? I'm in NY.

 

[blkgolfer1]

SBR711 help please!

0421 catalyst efficiency below threshold... PCM logic has determined cat to be bum based on sensor activity.. you can look at the honeycomb all you want, but it is inputs from from S2 that tells PCM what is going on, and logic decides from there based on a lot of other inputs..

GDS in current data for ox sensors, tthen graph mode, and watch the sensors toggle...

Cat is $7-800 depending on dealer attitude, add for gaskets, 3 new not at bottom, think it is 2 bolt and 3 nut that hold cat to manifold... come to think of it, I have 1 in shed I can take pic of..... forgot to take it last week Saturday when I scrapped 9 cats for $420...

Here is what the cat looks like...

I know this is a rather old post but it pertains to my situation I believe. I could really use your advice on this. I have a 3.5L that the dealer says needs a (1) new pre-cat but did not specify which one. I am a DIYer and just did the timing belt, water pump, plugs and coil packs on this 04 GLS. The same problem exists that was there previously, according to the dealer, in that it does not rev over 3000 rpm and if I attempt to it loses even more and runs even rougher or stalls. Any advice would be greatly appeciated.

 

[HyundaizednConfused]

QUOTE (Oxidation @ Jan 6 2011, 12:31 PM)


Just follow the pigtail off sensor to the connector,, you got the new sensor in hand ? I think the connector is above bell housing all tangled in with some other stuff.. You need to move forward and access it and unplug it.

sbr711 need your expertise....

04 Santa Fe 3.5 AWD

Misfire caused cats to get burned up. Threw the 421 and 431 codes. now it sounds completely plugged and as if it blew out a gasket or flexpipe and you can hear air hissing.

I picked up the 2cats for bank 1 and 2, but it sounds as if the rear one is where its plugged and air is escaping right before it.

ANyways I am quite the handy guy and have many tools including air, but I looked underneath vehicle and cant imagine doing this one myself. Transfer case has to be removed? and I assume most exhaust flange bolts are better off just cut?
I cannot afford to buy OEM rear cat, magnaflow 51005 will have to do.

can you point me to a link or page that shows the process at all?