ZeroFear

iTrader: (1)

The service engine soon light is on, and after scanning for codes I get a

Catalyst System Efficiency Below Threshold (Bank 1)
Catalyst System Efficiency Below Threshold (Bank 2)

Anyone know what this is? I would guess O2 sensor malfunction?

Mods are: Borla C/B, Lid, 80MM TB. Had mods on car for over 8 months with no light.

Any opinions?

2001NBMZ28

P0420 or P0430 is usually a bad cat, both simultaneously could be a symptom of something else going on. If it turns out to be the cats the 00-02 F-body warranty is 10 years/120K.

qwk93ta

iTrader: (13)

I had P0420 a few months ago and a local dealer replaced the cat for free.

jmilz28

iTrader: (13)

Likely bad cats. Warranty on cats and PCM is 8/80, not 10/120 last time I checked. I was a service advisor at a chevy dealer so I know, but it may have changed in the last year or two.

Make sure you tune that car and possibly replace the front O2s, I suspect you are running rich and that is what kills the cats prematurely.

2001NBMZ28

GM extended the 8/80K federal emissions cat warranty in December 2006, they sent letters explaining it to current owners.

jmilz28

iTrader: (13)

Good info! Thanks!

scottso

I have the same problem - they gave me a copy of the TSB when I went in. I have to get in to have it taken care of.

95hitam6

iTrader: (1)

damn my nissan has the exact code/problem but the dealership wouldn't fix it because theres no emissions law where i live. so i said screw it, i'm not paying 800+ bucks if its not hurting the car

Scoggin Dickey

iTrader: (34)

I believe it's a federal law, not local.

scottso

Yes, it is Federal law 8/80 on all vehicles (for cats). If you have a defective cat and fall in this timeframe the dealer is violating the law.

My understanding is that Federal law protects the computer for 8/80 also.

LS1>*

iTrader: (5)

Bad cats for sure......I installed RandomTech Hiflow cats that had been gutted and immediately got those trouble codes.

01WS6er

iTrader: (2)

I got the letter last yr explaining the cats to 10 yrs.

Fed law does cover cats to 8/80, ecm to 8/80 and maf to 8/80. I know BMW does anyway since I am a tech. These are covered due to emmissions.

nissan has problems with their cats and o2 sensors anyway. I am in the same shop as nissan. Those techs replace cats,02 sensors and TB everyday. I mean 2-3 a day.

MJK

iTrader: (3)

I was thinking the same thing as well.It is odd that both banks are getting the codes at the same time.That does USUALLY indicate something else is wrong further upstream.

Black01M6SS

iTrader: (3)

Gut the cats and buy o2 sims

LS1>*

iTrader: (5)

My car <3's gutted cats.......I believe HPTuners will tune out the CEL so no o2 sims would be required.......My Superchips handheld tunes it out, as in, the SES light doesn't come on due to them, but if you scan the car they show up.

2tone

iTrader: (1)

I have this same CEL code. I installed some brand new 1 3/4 ARH + catted Y. Like 2 months ago. MTI tuned it. So my cats are dead? If it's not hurting my car what do I need to do to just get rid of the CEL. How do you gut the cats? Or do I even need to?

I had the CEL deleted last week and it came back on yesterday. Thanks

scottso

You guys and the removing/gutting the cats drive me nuts. If I tried that in my state I'd be strung up by the b@lls.

New DS cat under warranty fixed my problem.

Of course, they sent me away with an exhaust leak once, then ~almost~ twice when I returned to have the problem corrected and they denied it existed. But that's a different story.

Black01M6SS

iTrader: (3)

We replaced some aftermarket "Magnaflow" cats today that were only a couple months old. The cats either take to long to heat up or they are to far away from the heat source and are taking to long to heat up either way they were new and causing the CEL to come on. I think they would work after a minute or two of crusing but at idle the rear o2's would be switching like the front and it would pop the code.

If yours is doing the same thing I would just get o2 sims to get rid of the code. It won't hurt anything as long as they are not clogged.