The dreaded light came on today. When I politely asked the truck what was wrong it told me P 0420. I looked it up and the winner is P0420 1/1 Catalytic Conv Eff
Does that mean the cat is junk?

 

Or hollow. Or the front O2 is lying..... or the rear O2 is just old and jaded..... How long have you had the truck? Is it possible a previous owner hollowed it out? Should be able to just clear the code, and call it a day. See how long it takes for it to come back.

 

It's gettin close to a month with the truck. The only history I have with it is getting over the tranny hurtle. Runnin like a top now. Upon close inspection of the truck now that I own it I expected that the exhaust system was going to need attention. Cat back goes from single pipe into a duel outlet muffler. Cat and forward looks tight but it's been there for a while.

 

is the pipe after the cat been changed? It might just be hollow.....

 

Last week there was a short pipe after the cat that went into a small muffler which then went into the bigger duel outlet muffler. The pipe out of the small muffler broke off so I got rid of the small muffler and replaced it with a pipe. So now after the cat the exhaust flows directly into the big duel outlet muffler. The cat is approximately 36" if not more in front of the muffler. The forward and aft O2 sensors were not touched. The CEL just came on today.

 

How did you remove that short pipe? Saw, may have jiggled the O2 sensor. Heat, needed with the sensor.

Maybe?

 

Mr.Sawzall, the first cut closest to the sensor was smooth not much vibration.
If the sensor was bad wouldn't it be a different code?
I wouldn't mind loosing the cat when the system gets replaced. Ive been reading about how to trick the sensors into thinking it's still there. As long as there's no codes I'd be able to get an inspection sticker.

 

Non-fouler trick. Works pretty good.

 

Man, aren't you living in the 80's. Now, it could be Mr., Miss, Ms or anywhere in between. I, myself, have several pairs of alternative lifestyle cutters (dikes).


Maybe just start with this, go from there...

 

[QUOTE=dbbd1;3332855]Man, aren't you living in the 80's. Now, it could be Mr., Miss, Ms or anywhere in between. I, myself, have several pairs of alternative lifestyle cutters (dikes).

Yeh well I can't count on nor do I want to coddle the alternatives. I know I can count on Mr.Sawzall. The dikes might have their use but not with I'm doing right now