p0420

[ThatShoGuy]

i keep getting this code

should i think just an o2 sensor is on its way out. with them having around 110k on them.

or the cats are really taking a crap.

what are the options i would gut them since i dont deal with emissions but pretty sure i read somewhere not to do that because the car will run worse. but my worry is they might be getting clogged.


what should i do guys????

thanks!

 

[rubydist]

P0420 says the cat is operating below the minimum threshhold, or that the cat is not doing its job. This could be a bad cat, or it could be that one of the o2 sensors (or more) is bad. The way to narrow it down is to have the o2 sensors logged in real time. Or, like I do on my Expy, just reset the codes periodically when it comes on and ignore it. As long as the vehicle runs well, I'd just ignore it, but that's just me....

 

[93rev2sev]

I think the 420 code means it's time to light up and say "screw it".

 

[frosho]

I have no idea what's goin' on...

 

[1bad98SHO]

More than likely the Cat has failed. You can try to "re-light" the Cats by running the engine for a good 15 minutes at 2000rpm with 2 coil packs disconnected. Sometimes this will work but most of the time it wont. Log all the o2 sensors and if the rear o2's are switching at a speed consistent of the front o2's and they seem to read the same readings then the cat has failed. In proper combustion the rear o2's will read slower than the front o2's

 

[ThatShoGuy]

More than likely the Cat has failed. You can try to "re-light" the Cats by running the engine for a good 15 minutes at 2000rpm with 2 coil packs disconnected. Sometimes this will work but most of the time it wont. Log all the o2 sensors and if the rear o2's are switching at a speed consistent of the front o2's and they seem to read the same readings then the cat has failed. In proper combustion the rear o2's will read slower than the front o2's

never heard of this "re-light" thing? what is it?

i did scan my car again today i just have a little autozone scanner and i have a p0133 code now up bank o2

 

[SHOmethewayhome]

make the sucker glow red, restart the catalyst process. i think what he's saying is run that sucker rich enough to make the EGTs hot enough to refire the catalyst, and use the fuel being dumped from the two spark-less cylinders to do it.

just a guess.

 

[ThatShoGuy]

some one have a more detailed info about how the "re-light" the Cats?

this is something im new to and would like all the details!

 

[stephen newberg]

This is strictly a guess, but what they might be talking about is burning off residue. Over time if the temps in the converter have been low, the surfaces of the catalytic materials could become coated with exhaust materials which would reduce the effectiveness of the converter. This would then also mess up the results from the 02 detector if it is downstream. If you bring the temps very high and manage to burn off any such residue, then the surfaces of catalyst are again exposed correctly and things start working as they should.

The only problem I see with this, in concept, is what temps might be required to remove the residue. At high enough temps the converter itself could easily be damaged, plus, of course, there is always risk of fire externally if there are flammables in the area, like spilled oil, loose whatever, etc.

I would think this is something you would do very, very cautiously, if at all, and with as many circumstances as possible tightly controlled.

pax, smn

 

[ThatShoGuy]

This is strictly a guess, but what they might be talking about is burning off residue. Over time if the temps in the converter have been low, the surfaces of the catalytic materials could become coated with exhaust materials which would reduce the effectiveness of the converter. This would then also mess up the results from the 02 detector if it is downstream. If you bring the temps very high and manage to burn off any such residue, then the surfaces of catalyst are again exposed correctly and things start working as they should.

The only problem I see with this, in concept, is what temps might be required to remove the residue. At high enough temps the converter itself could easily be damaged, plus, of course, there is always risk of fire externally if there are flammables in the area, like spilled oil, loose whatever, etc.

I would think this is something you would do very, very cautiously, if at all, and with as many circumstances as possible tightly controlled.

pax, smn

thanks for your input the motor dont leak any oil or anything like this, it is a nos short block with 14k on it so every thing is resealed

i have notices that the unhood temp feels pretty hot. but the temp gauge in the car still reads good.

i just took the intake off and removed the secondary's from the lower intake (there were already tied open) cleaned it resealed ever thing hope for it to run a little better.

also fixed a little leak in the tube that runs from the egr to the exhaust manifold that runs near the battery.