Aright...... I have a quick Q. I recently hit 80000KM which means my warranty is up and wouldn't you know, I get a cel. Its a P0420. dealership told me to try and change the plugs and air filter, does that seem right? The car has also been very hard to start lately also, usually taking up to 3 tries before it starts. Does anyone have any insight?

 

https://www.cobaltss.net/forums/show...ighlight=p0420

https://www.cobaltss.net/forums/show...ighlight=p0420

https://www.cobaltss.net/forums/show...ighlight=p0420

learn 2 search newb

 

I know how to search.....I already read all of those posts, and I do not have any aftermarket parts on my car which would throw the code. These links have nothing in common with me. I asked if what the garge told me was correct? Don't really appreciate the noob part either!

 

cats are known to go bad in these cars, thats the first place i would go, thats the cat eficiency code

plugs and stuff will not fix that code either. Either the sensor is malfunctioning or the cat is blown

 

your stock cat is probably pooched.
the stocker is known go go alot earlier than 80k also..

i throw the same code, but i have a header/dp highflow cat, and a small leak lol

 

well then i would take and have them look at my cat. and get a new 1 and problem solved

 

time for new cat..meow..the warranty on the cat i think is longer than ur standard warranty on the car...check wit ur dealers

 

Thay already replaced the cat at 45000Km. Do you think it would go bad again?? already?

 

yup, big big problem on these cars

 

hmmm its possible. the p0420 goes off in a few different times..if the cat is bad. o2 sensors read same voltage,or 1 sensor is bad..go to the dealer

 

very possible

 

that means you drive it hard too, because just cruising wont clog it as quickly, once you hit that gas pedal hard though and the stock tune with its utter richness kicks in, you are shooting tons of unburnt fuel and **** right at that thing

 

.......I am at a loss of words then....I hpoe i won't have to do this every 40K...geez! Thanks everyone, I'll start with that i guess

 

go catless

 

I just might!!

 

yup that what we did on our car , one of the first things too

 

yeah i mean the stock cats on our cars blow...i wud go aftermarket or just go catless as stated.

 

There free for 8 years 160,000 km(100,000 miles) or something like that under the emissions part of the warranty.
So what the hell ,If they are as bad as everyone says then they will most likely come up with a better one for the super charged cars.

 

REAR O2 SENSOR 100% of the time.
Get a 02 simulator or just tune it out with hp tuners.

 

The rear o2 does not go bad 100% of the time, its a problem with the cat especially because of the starting issue.

The car would not have a problem starting if the o2 sensor was bad. That sensor is just a system monitor sensor, just monitoring the cats efficiency. Its not like the front o2 which actually helps the car adjust the "tune" as you daily drive. When I say tune I mena part throttle and daily driving not getting WOT.

 

Just a note, what kills the stock cat is not that it is low quality but the stupid rich stock/S2 tune during WOT operation.

 

yup, check post #12, thats what I had said

 

Okay, I swapped out the plugs and cleanedthe air filter the P0420 hasn't returned since...As for the starting problem, The garage had changed the cam sensor housing and I am throwing a P0017 now. I read up on it a bit and I am guessing they have to do a case relearn or something to that sort? I read that is why I am having trouble starting? does that make sense?

 

p0420=new cat

 

crank sensor case relearn, that you have to take it to some one with a tech2