hey guys,

i just got a PO420 service code on my 07 g35s. they say my cat converter (the one on the drivers side) is bad and needs to be replaced. of course, dealer wants WAY too much.

i've done a search and read some other threads on this and some had mentioned that a cat should last the life of the vehicle. i currently have 210,000kms and the car still drives like new. i don't think there's anything wrong with my engine and my gas consumption seems to be normal (620km/tank on highway, 500km/tank mixed). what could have caused my cat to go bad?

i don't know if i can trust that the dealer knows 100% that the cat is bad. can they tell that just from the code? i have took a sniff of my exhausts and did notice the drivers side did smell different. does that mean the cat is bad?

also, i just did a smog test last year and passed.

can you guys give me some advice on what i should do? i'm out of warranty and don't want to give the stealership any more of my money.

should i just change all my O2 sensors?
should i get an aftermarket cat converter? will this affect the sound of my exhaust with 1 oem cat and 1 aftermarket?
if my cat is bad, am i causing any harm to my car by continuing to drive it without replacing the cat?

 

how many miles you got? I think by law they have to cover it for 70k... I'd personally get some RTP's and an uprev tune, or some HFC's - it'll be cheaper. Or another member who already did that can sell you a used one I have 2 in my garage. but they have broken bolts on them that need to get extracted when they got removed.

0420 wont do anything, except you'll probably fail an inspection. If you go to a tuner and get an uprev tune they can fix that for ya(unless you are in a state where they sniff the exhaust)

 

Well he's got ~130k miles so the warranty is up and no they are not supposed to last a lifetime and if the cat has gone bad then changing O2 sensors wont help as the inner core of the cat has probably deteriorated.

New oem cats can cost close to a grand so getting aftermarket HFC is a better option which will give you a louder sound for sure but will cost half the price of the oems and give you a few extra ponnies.

 

Sounds like an excellent time to upgrade to some HFC or ART pipes, if you get an osiris reflash you can turn that code off in the ecu also, it's fairly common with exhaust modifications

 

thanks.

can you recommend any that sound close to oem? (i don't want it any louder than it already is)

can i use 1 aftermarket and 1 oem cat? will this have any negative impacts?

 

Please don't try this.. It will not end well. Any high flow are going to sound similar, I recommend kinetix based on the value and quality

 

if you buy a HFC kit for our car, it should come in a pair anyways.

 

anyone here upgrade to HFC and want to get rid of their oem cats?

 

^ im pretty sure there are a lot of people who have HFCs and OEM cats sitting in there garage and would sell em for cheap, check out the marketplace

 

i was thinking the same thing, but haven't seen any recent for sale posts in the marketplace...

 

^ check myg37.com marketplace which is MUCH more active and has some going for sale every now and again, and yes the cats are the same

 

ok, i'll try that, thanks!

do you know if G37 cats fit our cars? will the G37 coupe cats fit also?

 

Didn't want to start a new thread. Quick question, I'm getting P0420 and P0430. Bank 1 and 2 of the cats efficiency threshold. I dont want to go buy o2 sensors because im not too sure if its the rear or front. Should i take it to get a diagnostics for $80 or go for new cats?

 

http://www.nicoclub.com/FSM/G35/

This is an O2 sensor code LOL. They die just like all other electronics. Open the factory service manual and look into the exact one is yours.