joeilesGXP

I all,
I was driving my ride yesterday when the check engine light came on. I used my predator to pull the code and it gave me P0420 catalyst threshhold when i ran the live date while I drive I noticed the one of the sensors read around 1100 degrees while the other read 32 degrees. is this a bad O2 or is the hi flow cat I installed bad. also If I clear it as soon as I turn the key it comes right back.

I appreciate all the help you guy's have given me in the past! I guess I am looking for some more help.

SILVER LS4

P0420 is a catalyst efficeincy code. Meaning the cat is not doing its job. I'd guess it would need a converter. If it's the stock converter, that can be warrantied to 8 years and 80 thousand miles. Also, 02 sensors don't read in degrees. Are you sure its not giving you volatage readings. The higher the voltage the richer its running generaly.

live2ride

I had run a complete log of my stock settings using the Predator.
The Cat bank 1 sen 1 had min temp of 789 and a max of 1158.
The Cat bank 2 read 32 in all settings.
The o2 volt bank 1 sen 1 had min of .0521 and max of .8984.
The o2 Volt bank 1 sen 2 had min of .5773 and max of .9505.

Are you running ver. 8r06? They released that to fix something with clearing the DTC codes.

When I was changing between tunes with 8r04 or 8r05 I remeber getting the check light and had trouble clearing the code. Not sure what code it was though. Just thought I let you know my stock temps are in line with your log.

joeilesGXP

yes I am running the newest version. I also am running a hi flow cat and downpipe from hogan. since I last posted I reloaded to tune and the light went out. drove the car all day and no check engine light. now I am confused.

Mgpeagle

iTrader: (6)

Sounds like you need a rear O2 sim. They work great by the way. I had one on my old 2001 GT. It had a high-flow RT downpipe and I got that same code before the sim went on.

-Mike

live2ride

How long has the cat been installed? I did a search on the code and found some interesting comments.

http://www.tegger.com/hondafaq/p0420.html

A snip from the link:

""The ECM monitors converter efficiency by comparing the voltage values of the heated oxygen sensor 1 (HO2S-1) and heated oxygen sensor 2 (HO2S-2). Under normal operating conditions, the HO2S-1 should vary between 10 mV and 1065 mV and the HO2S-2 should remain relatively steady between 500 mV and 800 mV. This steady reading of the HO2S-2 indicates a correctly functioning catalytic converter.

"When all parameters have been met, the ECM will run a 5 second DTC P0420 diagnostic at idle. The ECM will command rich and monitor the time it takes the HO2S-2 to go rich. It will then command lean and monitor the time it takes the HO2S-2 to go lean. The longer it takes the HO2S-2 to change rich/lean means the converter is storing oxygen and is functioning properly. If the five second test fails, the ECM may take several tests during several ignition cycles to set the DTC. DTC P0420 sets when the ECM has determined that the catalytic converter is no longer efficient."

Since it's an efficiency test and the lights off, I don't know how worried I'd be.

Good luck.

Area47

bad cat. not an uncommon problem.
i turn the ouside case of my cat blue if that tells you anything

Kazmaniac

I wanted to get the Hogan DP, are bad cats a problem or a one-off?

joeilesGXP

I gave them a call and described what was up. They are sending me a new down pipe and cat.

thanks for all the help.

joeilesGXP

Yea,
I pulled the same link up the other day. it sounds like that is exactly whats going on I called Hogan and they are sending a new down pipe and cat to replace the one I have.