Originally Posted by Mpower3

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.

Originally Posted by kingsleyop79

I would try to get the inspection done asap just in case the lights come back on.

Originally Posted by Mpower3

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.

Originally Posted by kosan

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.

Originally Posted by kingsleyop79

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

Originally Posted by gshadow325

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

Originally Posted by Pabst13

I also have been getting p0430 code as well as the VSC TRAC and VSC OFF lights on the dash. I just bought the truck, ‘04 Sport Edition 4wd w/203k miles. The prev owner said that the code was an O2 sensor but my technician says the Bank 2 CAT is bad. The downstream sensor seems loose, washer shakes, and it looks to have an exhaust leak at the junction just prior to the O2 sensor. Could a leak there cause a prob and trip there code? I’ll keep trying to upload a pic, but there looks like black burn marks on the flange and the support/nut is rusted when literally nothing else on the undercarriage is.