P0420 & P0430 Codes - 03 4Runner 165K

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kingsleyop79

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Long time reader, first time poster:

I have a 2003 Toyota 4Runner with 165K miles on it. I bought the truck in Jan 2008 with 59K. It seems I may need one or both front cats replaced. I believe I have the Cali spec -- 4 catalytic converters.

A couple of mechanics have said not to use aftermarket cats, but spending upwards of $2000 on OEM cats doesnt make much sense to me -- this vehicle would get me maybe $5-6K in my area. I don't see many posts from 4th Gen owners who installed aftermarket cats on their own vehicle about the quality/durability (or lack thereof).

Are there any worthwhile replacements? Is universal or direct fit any different for the vehicle? Is it possible to get aftermarket which lasts up to 2 years?

I guess I would say I'm looking for 4th gen owner aftermarket cat testimonials. Thanks...
 
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kingsleyop79 said:
Long time reader, first time poster:

I have a 2003 Toyota 4Runner with 165K miles on it. I bought the truck in Jan 2008 with 59K. It seems I may need one or both front cats replaced. I believe I have the Cali spec -- 4 catalytic converters.

A couple of mechanics have said not to use aftermarket cats, but spending upwards of $2000 on OEM cats doesnt make much sense to me -- this vehicle would get me maybe $5-6K in my area. I don't see many posts from 4th Gen owners who installed aftermarket cats on their own vehicle about the quality/durability (or lack thereof).

Are there any worthwhile replacements? Is universal or direct fit any different for the vehicle? Is it possible to get aftermarket which lasts up to 2 years?

I guess I would say I'm looking for 4th gen owner aftermarket cat testimonials. Thanks...
Click to expand...

Are you sure your cats have gone out and not just O2 sensors?
 
kingsleyop79 said:
Long time reader, first time poster:

I have a 2003 Toyota 4Runner with 165K miles on it. I bought the truck in Jan 2008 with 59K. It seems I may need one or both front cats replaced. I believe I have the Cali spec -- 4 catalytic converters.

A couple of mechanics have said not to use aftermarket cats, but spending upwards of $2000 on OEM cats doesnt make much sense to me -- this vehicle would get me maybe $5-6K in my area. I don't see many posts from 4th Gen owners who installed aftermarket cats on their own vehicle about the quality/durability (or lack thereof).

Are there any worthwhile replacements? Is universal or direct fit any different for the vehicle? Is it possible to get aftermarket which lasts up to 2 years?

I guess I would say I'm looking for 4th gen owner aftermarket cat testimonials. Thanks...
Click to expand...

v6 or v8?

you can tell your couple of mechanics to shove a fist up their @ss. those parts changers dont know what they are talking about.

i have a v8 with aftermarket cats. now with over 10,000 miles on them. No issues.
here is my thread tracking progress of the problem
http://www.toyota-4runner.org/4th-g...20-yes-i-searched-maybe-i-am-doing-wrong.html
 
If you have both 0420 (bank 1) AND 0430 (bank 2) it is more likely you have a different problem than the cats.

The following engine related problems are known to generate the PO420/30 codes:

Intake manifold air leaks
Fuel injector problems (leaks)
Incorrect spark plugs
Ignition timing
EGR problem
Defective catalytic converter
Oil or antifreeze entering exhaust
O2 sensor not operating correctly
Road damage to converter
Silicone contamination

Since your issue is affecting both sides you more than likely have a fuel related issue. At least that is where I would start the diag process. It's not likely that both O2's or both cats failed simultaneously. It is possible that both cats have failed, but there would be another underlying issue that caused it.

As far as aftermarket vs OE. I think OE is the way to go, although many of the issues with aftermarket cats being perceived as bad are because the cat was not the problem in the first place.
 
gshadow325 said:
v6 or v8?

you can tell your couple of mechanics to shove a fist up their @ss. those parts changers dont know what they are talking about.

i have a v8 with aftermarket cats. now with over 10,000 miles on them. No issues.
here is my thread tracking progress of the problem
http://www.toyota-4runner.org/4th-g...20-yes-i-searched-maybe-i-am-doing-wrong.html
Click to expand...

Thanks for response. I have a 4.0 V6 4WD Limited engine. So from my understanding, you replaced the pair of front cats (manifold cats nearest the engine) with Pacesetter, all 4 sensors and used spacers on the 02 (rear) sensors?

Does your truck have 2 cats or 4? I looked at the manifold through the posted link and I'm not sure if that would fit a truck with 4 cats?
 
Thanks for responses so far. I will first use the "temperature" test pre-and post-cat on both front cats. If that fails (post is same temp or cooler than pre-cat) then I will look into aftermarket replacement. If its both cats OEM is just not a realistic expenditure, especially if there is another underlying repair to be done...
 
Start with all 4 o2 sensors , then gshadows fix & if that doesn't fix it , then go from there ! Just did the pacesetter manfolds on mine so far so good , but I do have urd y-pipe . Fairly easy on rear 2 & pass. side is ok but drivers side is a bit*$ no room for your hand or tools .I had to use 3 different wrenches 22m I believe . Denso is oem & amazon I found had best prices .
 
kingsleyop79 said:
Thanks for response. I have a 4.0 V6 4WD Limited engine. So from my understanding, you replaced the pair of front cats (manifold cats nearest the engine) with Pacesetter, all 4 sensors and used spacers on the 02 (rear) sensors?

Does your truck have 2 cats or 4? I looked at the manifold through the posted link and I'm not sure if that would fit a truck with 4 cats?
Click to expand...

this is why i asked about v6 vs v8.

i replaced the front cats with pacesetters, quick search yeilded 750045 and 750046 are the parts YOU need for a v6 49 state vehicle, they $350 and 375

what i would do in your case. from experience i would do this.

drive your truck with the rear window cracked open a little bit. check if you smell rotten eggs stink. if you do, you have bad cats. if you dont, there might still be hope and its just sensors going bad.

buy from rockauto.com all the oxygen sensors, should be 4. buy the denso oem ones. find a coupon code for rock auto. they always have 5 or 10% off floating around.

yes all 4, around $300 for the 4.

why?

if cats are bad, sensors are bad too.
if sensors are bad, and that fixes your problems then you dont have to spend the money on cats, headstuds, bolts and labor.
if sensors dont fix your problem still and you dont have stinky rotten egg exhaust, you can cheat and do the spark plug fouler mod for $10.

actually right now with the two p420/p430 codes you can do the spark plug fouler mod and it might work. in my case, i did not want to cheat since i wanted a properly running vehicle for the long term.

then again, my advice is subjective because i have a v8 and might be different scenario than your cali emission v6. none the less i feel your pain with the mixed advice from your mechanics and then us online mechanics LOL. if you are lucky hopefully someone can chime in that was in a similar situation like yours.

good luck
 
gshadow325 said:
this is why i asked about v6 vs v8.

i replaced the front cats with pacesetters, quick search yeilded 750045 and 750046 are the parts YOU need for a v6 49 state vehicle, they $350 and 375

what i would do in your case. from experience i would do this.

drive your truck with the rear window cracked open a little bit. check if you smell rotten eggs stink. if you do, you have bad cats. if you dont, there might still be hope and its just sensors going bad.

buy from rockauto.com all the oxygen sensors, should be 4. buy the denso oem ones. find a coupon code for rock auto. they always have 5 or 10% off floating around.

yes all 4, around $300 for the 4.

why?

if cats are bad, sensors are bad too.
if sensors are bad, and that fixes your problems then you dont have to spend the money on cats, headstuds, bolts and labor.
if sensors dont fix your problem still and you dont have stinky rotten egg exhaust, you can cheat and do the spark plug fouler mod for $10.

actually right now with the two p420/p430 codes you can do the spark plug fouler mod and it might work. in my case, i did not want to cheat since i wanted a properly running vehicle for the long term.

then again, my advice is subjective because i have a v8 and might be different scenario than your cali emission v6. none the less i feel your pain with the mixed advice from your mechanics and then us online mechanics LOL. if you are lucky hopefully someone can chime in that was in a similar situation like yours.

good luck
Click to expand...

Makes sense. I dont think I've ever noticed rotten egg smell, or "loss of power" that they say comes with bad cats. No rattles either except for heat shield. The only check left is the pre and post-cat heat temp check.

I hope sensors helps. I don't want to change cats. If I were a "builder" I could keep the truck as a project but I'm not even close. All work at mechanics = $$$.

BTW great job on your truck! Any estimate of number of hours total on mods?
 
Thank you. I would say I have a few hours in here and there. ...ehh maybe 2 or 3 hours lol.

Think about it like this. If you change the sensors and you get better mileage it would pay off in the long run. Also 165k is pretty darn good for oem. So putting in a few bucks for another 100k isn't too bad right?

Change them and do a positive to ground to reset all the adaptives.
 
Cats: An Update

I changed the sensors last July. The PO430 and PO420 codes re-appeared after a couple of weeks. Now I notice the occasional exhaust smell in the cabin (not quite sulfur though). There seems to be a rattling sound in the exhaust pipes, possibly from the cats.

I bought universal cats for welding installation, but I was told that this is only for the rear cats (my vehicle has 4). Now, I am pricing direct-fit aftermarket cats. I refuse to spend $1000+ per cat plus labor. The vehicle is 2003 with 175K on it.

I have seen the following brands/prices on Amazon.com:
Pacesetter 750045/750046 $376/262
Dorman 674-796/674-797 $262/281
Magnaflow 50848/50849 $359/427
Eastern 40598/40599 $310/316

All of these cats fit NY inspection specs. I need to change the cats asap to pass NYS inspection.

I only saw reviews for the Dormans and Pacesetters. Dormans seem to have better reviews. Does anyone have any experience with these converters?
 
kingsleyop79 said:
I changed the sensors last July. The PO430 and PO420 codes re-appeared after a couple of weeks. Now I notice the occasional exhaust smell in the cabin (not quite sulfur though). There seems to be a rattling sound in the exhaust pipes, possibly from the cats.

I bought universal cats for welding installation, but I was told that this is only for the rear cats (my vehicle has 4). Now, I am pricing direct-fit aftermarket cats. I refuse to spend $1000+ per cat plus labor. The vehicle is 2003 with 175K on it.

I have seen the following brands/prices on Amazon.com:
Pacesetter 750045/750046 $376/262
Dorman 674-796/674-797 $262/281
Magnaflow 50848/50849 $359/427
Eastern 40598/40599 $310/316

All of these cats fit NY inspection specs. I need to change the cats asap to pass NYS inspection.

I only saw reviews for the Dormans and Pacesetters. Dormans seem to have better reviews. Does anyone have any experience with these converters?
Click to expand...

I had similar problems changes sensors and problems came back.

I solved it by trading in my 2004 for a 2013.
 
If aftermarket, I would go with Magnaflows, but I would check first if its not the O2 sensors going bad first
 
Crazy - I just got these codes on my 4runner. 146,000 on a 2004 4.0 V6. Within the last 5,000 miles I had my plugs changed too. Disconnected the battery last night and did one drive cycle on way to work this morning and will see how the ride home goes. Worst part is my emissions are due this month. Hopefully it doesn't come back but my guess is it will and then I'll have to try the fouler mod and if that doesn't work, new O2 sensors.
 
Mpower3 said:
Crazy - I just got these codes on my 4runner. 146,000 on a 2004 4.0 V6. Within the last 5,000 miles I had my plugs changed too. Disconnected the battery last night and did one drive cycle on way to work this morning and will see how the ride home goes. Worst part is my emissions are due this month. Hopefully it doesn't come back but my guess is it will and then I'll have to try the fouler mod and if that doesn't work, new O2 sensors.
Click to expand...

I would try to get the inspection done asap just in case the lights come back on.
 
kingsleyop79 said:
I would try to get the inspection done asap just in case the lights come back on.
Click to expand...

I reset the codes, drove it around for 50 or so miles and went in for a inspection. They knew I reset it and asked me to come back in 7 days. haha.

Anyway, I had the same problems. First, replaced the O2, then had to replace the Cats.
 
Well I went and got it tested on Saturday and passed!!!!! Had driven it about 100 total miles from the time I reset the code to the inspection station.
 
Mpower3 said:
Well I went and got it tested on Saturday and passed!!!!! Had driven it about 100 total miles from the time I reset the code to the inspection station.
Click to expand...

Glad it passed! I have to do the same (again). OK so you say you replaced the cats AND 02 sensors? And the lights are still coming back on?

I just had Magnaflow cats installed but the codes are still coming back up, and the car runs worse (idles rough) than with the old burned out cats...
 
kosan said:
I reset the codes, drove it around for 50 or so miles and went in for a inspection. They knew I reset it and asked me to come back in 7 days. haha.

Anyway, I had the same problems. First, replaced the O2, then had to replace the Cats.
Click to expand...

Did you replace the cats and still get the same error codes?
 
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