Easy methods to try and get rid of p0420

I've heard lacquer thinner in the gas also have heard sea foam a
In the gas any other ideas I really don't think it's my cat but I could be wrong I'm still getting 27 mpg on ave it's a 2000 2.4 with only 77k miles are there any possible ways to test o2 sensor without a shop or test the cats money pretty tight right now.

 

clean 02 sensor or replace. clean air intake. clean maf. clean throttle body. replace air fuel ratio sensor

 

If money is tight, I wouldn't recommend putting lacquer thinner in your gas tank... I'm no expert but I believe you would be buying a new motor after that. Wait until you have enough cash to get it tested/fixed. Some shops will give you a free estimate.

 

your sensors will go bad before the cat will

 

Yea I'm not positive but I don't believe it is the cats will running sea Foam through the gas tank clean the o2 sensors up

 

I recently used the Spark Plug Non Fouler method described in this link:

http://honda-tech.com/showthread.php?t=1841240

I used it on my 2005 Tundra, I had the engine light on for almost a year, I scanned it and it was the P0420 code.
After I did the non fouler mod I cleared the code, then I completed a full drive cycle (this is needed here in california or you will not pass smog check), scanned it again and no codes were registered. Next day went to the smog test station and passed.

Scanned it again a few weeks after the smog test and still had no codes registered.

Hope this helps.

 

I don't want to hide the problem just was curious if there was a easy way to tell what the problem was

 

The URD o2 sensor simulator will probably fix the code 420. I haven't tried it yet. My 420 code is just pending and hasn't set off the light yet. I have a slight miss in the idle, and I think I could get better mpg. I'm gonna run the seafoam for a while and see if things improve. I have seen improvement after 2 tanks of gas with seafoam, but it could idle better. I will pull codes again soon and see if it's still pending, and may go with an o2 simulator.

 

i have just went through this only with a v 6. i purchased the truck with the deal that the trucks engine light is out. it had the same code as yours does. i got it with the light off and within 75 km the light came back on. the mechanic replaced both the upstream and the downstream and still no fix. then i went to an older friend who gave me the lowdown. when the emissions are not up to specs through the readings from the sensors, the ecu will cut the spark to a selected cylinder every once in a while to dump extra fuel into the cat, or cats in my case, in an effort to get them to light up and burn. what is happening is that the cat, or cats is unable to light up and burn the unburnt hydrocarbons coming out of the motor, and the downstream is sensing that there is no change in the exhaust hydrocarbons. if you plug in your obd 2 and can look at live data, get the truck up to full operating temperature and look at the o2 sensors. im not shure what they are referred to on the live data screen, but the upstream (closest to the motor) sensor resistance will jump around a bit, whereas with the downstream (after the cat or cats) should maintain a constant reading, even as the motor is revved. if the reading is jumping around, the cats have "bit the cookie" and are not burning the unburnt hydrocarbons. after the cats were replaced, it was like a whole different truck. it was more powerful, smoother and quieter, but i did not moniter that much of a change (if any)in fuel economy. good luck!!

 

This explains my misfire.

 

i replaced both of my cats and it completeley fixed the problem. the guy i bought it off of left the old sensors in the truck when i bought it, and when i installed the new cats i put in the old sensors just to see and the light went off after a bit of driving. i then sold the new sensors on kijiji. the pair of cats were about 600$ up here in canada. luckily the seller offered to pay half for me .
my experiance is on a 2001 tacoma trd with a v6 3.4l. good luck

 

oh and as well laquer thinner will definitley light up the cats, but it would light them up too much and melt them out. inside the cats are hundreds of platinum honeycombs that the hot gasses blow through. and make red hot. the red hot combs light up anything burnable. once they get too hot (by dumping obscure burnable substances through) theyll just burn out some of the combs inside, therefore making them useless. i would also assume it would melt out the exhaust valve??!!