p0420 & p0430 CEL

[Sackie]

Hi fellas. 01' cvpi 100K. I recently hollowed out my cats and bolted them back on with no physical problems. As expected I now get the two codes indicating cat failure on both sides - a result of rear sensors not seeing any difference from the front ones. No big deal - except now Im getting a little less MPG. Also noticing a little less power.

Questions - Does this CEL code trigger an open loop setting a fuel ratio to a one-size-fits all? I thought only the fronts did that, but with this constant CEL, I figured it's worth a guess on my problems.

I have spacers on order to removed the rear o2s from the direct stream which is supposed to fix the CEL, but info online I'm finding is conflicting and just guesses.

[cvpi guy]

i cant tell you about the open loop thing but i can tell you that the spacers most likely wont work as they didnt for me but i was able to get a o2 sensor simulator from www.O2SensorSimulator.com one is all you need for both of your rear o2's and it works great

they also sell on ebay

http://cgi.ebay.com/ebaymotors/O2-Ox...57699698QQrdZ1

[reekor]

I'm not sure why you hollowed out the cats, but yeah your pcm is going run in an open loop since your o2 are now reading out of range (cold engine setting). Your air/fuel mixture is controlled by 02 readings. From what you said, it's now running rich.

Originally Posted by Sackie

Hi fellas. 01' cvpi 100K. I recently hollowed out my cats and bolted them back on with no physical problems. As expected I now get the two codes indicating cat failure on both sides - a result of rear sensors not seeing any difference from the front ones. No big deal - except now Im getting a little less MPG. Also noticing a little less power.

Questions - Does this CEL code trigger an open loop setting a fuel ratio to a one-size-fits all? I thought only the fronts did that, but with this constant CEL, I figured it's worth a guess on my problems.

I have spacers on order to removed the rear o2s from the direct stream which is supposed to fix the CEL, but info online I'm finding is conflicting and just guesses.

[Sackie]

It's been a week and a lot of driving since I installed those spacers on the rear O2 sensors and reset the computer. The CEL is gone and hasn't come back which means it's passing the self test emission program. So I guess the claim is true in my case. Thanks for the replies.