P0421 Code

[joe944]

Took my car in to get the o2 sensor fixed. Walked out and the mechanic told me the catalytic convertor light was going to go on. Sure enough it did. Or at least it is showing code P0421. Is that the convertor ? Is the car in trouble if you will to drive ?

 

[joe944]

car has 206,000 miles on it. thought the converter would last longer ? anyone with the same issue ?

 

[pcb]

That is your pre-cat. If it gets raw fuel on it it can burn up in minutes.

When that code goes off, your car goes into limp mode then wastes gas and you've got no power.

You guys in California are pretty much forced to buy the OEM original pre-cat because nothing else qualifies,.. (but apparently there is a company trying to get an after market version that qualifies.)

There is a trick that will clear the code and take it out of limp mode but the dudes that do your emission inspection are supposed to visually inspect everything to make sure it's all original equipment.

 

[agr99]

I did the non fouled trick and painted it black.two days later went and did my smog.passed with flying colors.I dont think smog people know what our o2 sensors look like

 

[joe944]

anybody else have problems with their cat ? I have had more than one car in excess of 200k and never had to replace the cat.

 

[MrGiggles]

Have you owned the car since new? If a coil pack fails (they often do) and the car is driven on two cylinders, the unburnt fuel gets pushed into the cat, creating a huge amount of heat that will damage it in short order. Chances are this has probably happened once or twice in the life of the car, and led to an early death for the cat.

There are ways to get around it, but they may not be applicable in CA.

 

[joe944]

Thanks, things are starting to make sense.

 

[steve_k]

Had to replace my cat at about 100k, and being in CA at the time the dealer part was all I could get.

 

[joe944]

I ended up ordering a megan from importreplacementparts.com. Direct fit. Should be CA legal. Much cheaper than dealer thankfully. Will see how it goes. Not sure what I am going to do with the car at this point.

 

[joe944]

Car has been solid outside of a bad timing belt job. Difficult to put money into a car that is not worth anything. But, like everyone knows on this site, a comparable car would be much more expensive not too mention the insurance costs. Thanks for your help.