asianice25

So the misfores now gone, and now ive got a code for PO420, and it showed up right after i changed my PCV Valve to a 2002 Z06 model PCV. This was the code for bank 1. So does this just mean that my driver's side cat isnt doing anything anymore? It isn't boggin down or anything. Can I drive it like this for awhile? Will it have a negative effect on my motor???

NEWBIE T/A

I dunno if it holds true for '01's, though.

Emmissions warranties run for 5/50 on these cars (non-California) , so it may be wroth your while to go to the "friendly dealer".

Oh, Auto Zone can pull codes for free asssuming the trouble light is on - perhaps they can help troubleshoot your problem.

Good Luck !


Britt

2K2SOMSS

Clear the code out and see if it turns up again. If it does then take it to the dealer for a warranty fix.

asianice25

Thanks for the info. Im getting mac headers with an off-road pipe i a month or so, so i think im going to skip the dealership, and just mod away. As long as it wont hurt my car while i drive it like this. I dont see why it would, but i wanted to make sure. Thanks.

Scott

Pro Stock John

Are you getting "Catalyst system below threshold efficiency?"

I used to get that back in 99.

I used to think that the cats were taking too long to light off, I had just did Grot headers and cats.

But you mention that you swapped your pcv...

Hmmm.

On cold start the pcm dictates the fuel, air and spark. Car runs intentionally rich. The AIR system pumps in air. I wonder if that pcv that you swapped in is either (1) not working properly or (2) is not calibrated for the car.

Please fix that before you put on headers, it does not affect performance but you might get other codes so get rid of this one so the light does not stay lit up... Shoot me an email if swapping the EGR fixes the problem.

asianice25

I'll see if that's a problem. I kept the old pcv, so maybe putting the old one back in will help. I was simply told that the 02 Z06 model ocv has faster valving, and that helps to reduce the carbon buildup in the motor. I guess some 4.8, 5.3, and 6.0L truck motors were having a problem with carbon so bad that it was causing misfires, and the 02 Z06 pcv was the fix. Ill switch it this weekend though, and have it scanned and see what happens. My ls1 is practically a ls6, so i dont see why the different pcv would make that big of a difference, but ill see whats goin on. thanks.

Pro Stock John

Hard to say, but it's possibly the culprit, because over the last five years I have never seen any of the other boltons cause that SES lite.

I have seen PCV's fail and there is a TSB for the 98 PCV's failing, so I lean towards that as the cause.

The code basically means that the cats did not adequately scrub the cold start emissions per the test that is picked up by the rear 02's. So the car ran dirtier than expected.

asianice25

maybe the crap is all coming out now that I've put the new valve in. It's kinda strange, but the misfire stopped after the new pcv, and the new PO420 catalyst inefficiency code came on. Is it possible for the car to be "cleaning itself out" a bit? other than this, i may just have bad cats, i know that my juice is running pretty rich, but i only have 22k miles on the thing. if the problem was to rememdy itself, would the ses light shut off? or would it stay on?

Pro Stock John

The light can go off after a certain number of keyed starts but when I got that code it will go off every couple of weeks.

I'd change the PCV back, the pcv does not blow carbon out you might want to a do a search in the 'external engine' section of LS1Tech on GM Top engine cleaner to burn off the carbon the right way.

asianice25

no, the pcv doesnt just blow out carbon, but it is directly related to crankcase pressure. If the valve isnt flowing up to par, it may be the cause of past carbon build-up. ill do a search on the carbon cleaning...