had a CEL and plugged in OBD, the code was p0420 or something like that, it said catalyst below efficiency. anyone know what this means and how to fix it?

 

it means the catalytic converter is no long working and needs to be replaced

 

the only exhaust piece i have changed is the muffler. i don't know much about cats and stuff because i don't have emissions where i live. probably an open ended question but would it be the cat on the dp or the one in the middle of the exhaust system?

 

its the one the front down pipe, the one in the middle is just a resonator

 

I am about a month out of warrentee on my 06 ss/sc, I had the car die on me one day, with the PCV fault (I think thats it) but then shut down and start up and all was good again. Then about 200 miles later the P0420 code came up. Is the Cat warentee longer then the standard 3yr/36k miles? and I can get it fixed for free?

I am also now getting only about a 4k redline and then it goes down to 3k in 4th gear +

Any help would be great.

 

IL has a 10 year 100,000 mile state warrenty. check your o2 sensor... the metal cap that goes over them came off mine... GM replaced both sensors for free.

 

yes all emisions equip. On any new vehicle is warnt till 80 or 100k ( i forget) i actualy belive its a law...... Corext be if i wrongaybe u should google it.

 

means your cat is holding too much oxygen and not enough harmful emmisions. means that cat is failing. however if you have a highflow cat then you need to retune the computer for it or you'll get that same code. i got an 0420 when i put the full hahn system in.

uhm, no. the one on the front of the downpipe is the flexpipe. the one in the middle of the downpipe is the cat.

nvm, read his post just above yours.

 

8yr/80k mile federal emissions warranty covers the cat and the pcm

 

cool, thanks, and I will give the car a good once over before I take her in. (I am a stock GM stage 2 car)

 

aparently the Cat went bad, and was causing the car to run gimpy. It is being replaced under Warrenty. Yeah For me. The local Chevy dealer is great.