This mourning i got this code. Autozone printed out a receipt that says- The PCM has determined that the catalyst system efficiency for bank 1 is below threshold. Bank 1 means cylinder#1. Any ideas or help would be greatly apreciated. Thanks. I have a highflow cat, i dont know if this has anything to do with it?

 

bump.

 

Well I know SRT-4's are different from EVO's, but on an SRT-4 the P0420 code is Catalyst 1/1 efficiency below required level. Hope that helps.

 

uh, bank 1 doesn't necesseraly mean cylinder 1, especially when talking about the catylist system. Has something to do with your hi flow cat im sure.

 

So could this mean my highflow cat is not as good as a stock cat? Not cleaning the gases enough before leaving the cat?

 

I thought the 420 code meant it is time to smoke..

 

Bob Marley CD time. BTW, its the hi-flow cat.

 

That too, its your car telling you that you are driving too fast....smoke a doob and you'll slow down for sure, probably run 45 in a 55...LOL

na, seriously, its saying your cat isn't working properly(according to stock cat specs). Your hi-flow cat is doing exactly what you bought it to do, be less resrictive.

look in the how-to section to find out the mecanical fix for your rear o2 sensor. its a simple fix, and you won't get a cel.

 

P0420 - Catalyst System Efficiency Below Threshold (Bank 1): Indicates Bank 1 catalyst system efficiency is below the acceptable threshold.

Possible Causes:
· Malfunctioning ECT/CHT
· High fuel pressure
· Damaged exhaust manifold
· Cylinder misfiring
· HO2S wiring concerns (shorted or chafed, bent pins, etc.)
· Damaged exhaust system pipe
· Damaged muffler/tailpipe assembly
· Retarded spark timing

Damaged Catalytic Converter:
· Use of leaded fuel
· Oil contamination/consumption
· Silicone contamination (sealants/cleaners)

From: http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm

My guess is that your High Flow Cat is causing the computer to think that you have a damaged cat and is throwing the code. My suggestion is to do the mechanical 02 fix, found in the how-to section. Or to get the 02 simulator.

 

^^

 

just get an 02 simulator and call it a day

 

WOW, Thanks for the replys. Keepem coming. I know a couple of you guys run test pipes. Do yall get this code?

 

http://www.forums.evolutionm.net/showthread.php?t=98573

mechanical o2 fix. works like a charm, and no cuttin and splicing wires like an o2 simulator. total cost is less than $3

 

i got the code, even with a o2 simulator installed...this prompted me to do the mechanical fix and i haven't had a code since.

 

If i do the fix, will I still pass emissions?