p0420 code, inspection failed

Posted: Wed Jun 03, 2009 5:01 pm Post subject: p0420 code, inspection failed

I have not been able to verify what bank it is atm.
I am thinking that it said bank 1 sensor 1 but cant locate it at the moment

I am using a mac tools OBDII scanner,
it states the following:
P0420 1/1
Cat. efficiency below threshold
Bank 1

when i go into to I/M readiness codes, it says that some are still in not ready status.
They are as follows
htd catalyst - n/a
sec air system - n/a
A/C refridge mon - n/a
Oxygen sensor htr - inc

all others are OK status

The guy at the inspection place told me that i had 2 not ready states that i had to take cover to pass. go and drive 75 miles or so and come back then. Per his sheet i failed for the following:
Catalyst and o2 sensors not ready

when i take o2 readings on the banks, they go up and down like they are supposed. If you need the parameters, i can get them.

How to fix before end of the month so i can get my dumb sticker!!
thank you for your help.

I have the following mods.
U bend delete, FW intake, PCM upgrade, 3.4 Pulley installed, performance shift option, AL104's, 3' ZZP DP, PLOG,180 Tstat

Posted: Wed Jun 03, 2009 5:44 pm Post subject:

You need an o2 spoof for the sensor behind the cat
_________________
1998 Silvermist GTP Coupe
Bone stock unicorn
1998 True Green Metallic GTP Coupe
Pullied, cammed, intercooled. With a kiddie seat. It once ran a 13 flat.
1998 True Green Metallic GTP Sedan (retired)
Stock: 14.33 @ 96.5
PB: 13.89 @ 101 mph

Posted: Wed Jun 03, 2009 6:21 pm Post subject:

420 is usually the rear o2 sensor... change it, spoof it or shut it off with a tuner.. and as far as the 75 miles, thats a crock of shit.. i can get monitors set in 15mins of driving all but usually evap which runs usually key off for most cars.

Posted: Wed Jun 03, 2009 8:24 pm Post subject:

Thats what i was thinking as well.
I am gonna do some more investigating and try to get it deleted.
I want to buy credits so i custom tune it anyway, so it will work out good.
lets say i go with the sim, is there anyway to keep that line in the engine bay instead of strapped to a piece of the support for the exhaust. I am nervous of the heat issue.
maybe i buy it, put it on, get the sticker and put it back the way it was. What do i care as long as it is the same code over and over.
thanks for your help.

Posted: Wed Jun 03, 2009 8:40 pm Post subject:

well the rear o2 does help with fueling and allows you to monitor how rich or lean you are, esp in boost at wot. even on our 500+hp turbo monte i run the rear o2. i would probably change it , unless your going to run a wideband.

Posted: Thu Jun 04, 2009 7:12 pm Post subject:

"You have 2 not readies cause the EVAP check happens only after the HeatedSensor goes ready"

How do i get this to go to a ready state?

Posted: Thu Jun 04, 2009 9:25 pm Post subject:

Posted: Thu Jun 04, 2009 9:40 pm Post subject:

Posted: Thu Jun 04, 2009 10:13 pm Post subject:

On the '02... still turn off those codes, but leave the rear sensor in the exhaust stream. Long story, but if you don't have an actual rear sensor in the exhaust, you'll be seeing some solid max positive fuel trims randomly during cruising, wasting gas and sometimes causing hesitation during this "stupid mode". It's a cat diagnostic it runs multiple times during each drive, looking for a change in the signal, regardless if the codes are shut off.

- Dave

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