CHECK ENGINE LIGHT

2.4, check engine light just came on, the code is p0420 does anyone know what the problem likely is and how to fix. The truck just turned 190,000 miles.
Thanks for your input.

 

Looks like bank 1 O2 sensor. At 190k it doesn't owe you anything.

 

Steve, are you saying its needs the oxygen sensor replaced? How big a deal is that? Any harm to the engine driving it?

 

Found possible fixes on another thread...thanks

 

From what I am reading on other threads, this may need a new Cat. My question is can you reuse the existing sensors or do you have to buy new ones?

 

I would get new O2 sensors first, then if that doesn't work, get a new cat. I wouldn't put a new cat on with old O2 sensors anyway, it may hurt the life of the new cat (money down the drain)

 

Clay...that makes sense, but I hate to spend that kind of cash on this truck with 190,000 miles, on a part that really has nothing to do with performance of the vehicle. We have no emissions testing here, can you eliminate the Cat and sensors...what does that do to the ECU and engine lights?

 

Leaves them on, just like it is now. Problem is, if something else pops up, you won't know, as the light is already on.

If it's the heating circuit of the sensor, I'd agree, it has little to do with performance, just some cold start emissions.

If it's the actual sensing function, and it's the pre cat unit, then it will have a lot to do with the performance, particularly fuel economy.

If it's the post cat sensor, then you are more up in the air over it being the sensor or the cat, as the cat health is it's prime function.

 

I have deleted cats before on our farm trucks growing up in texas ( they start hay fires fast) I just cut open cat, knocked out platinum or whatever is in there, welded it back up, then just put a resistor in place of the post cat 02 sensor, the fool the truck, then the front one will take care of the fuel mixture. The rear one is there to sense how well cat is working while heating up, and if it's scrubbing the molecules right, it will let your idle speed to return to normal. I think..