Xeremeh

Hey guys,

Awhile back my CEL started going off. I checked it with my XCal and saw:

P0430: catalyst system efficiency below threshold (b2)

After a little research around the net, I've seen everything from bad O2 sensor, to a bad tune, to a bad cat, to oil in the exhaust, to bad spark plugs. I installed headers and mid myself. Mid has cats. I put in my CAI and brenspeed tune at about the same time. So I'm wondering what I should do here. Are there any tests I can run to figure out exactly what the broken issue is without spending an arm and a leg?

Thanks!

Nuke

I'd get advice from the Brenspeed tech guys before doing anything.

2007VistaBlueGT

+1 Most likely a tune issue.

tx_zstang

Jeremy, I see this code too on one of my cats, and then eventually over time, the other one posts it as well (0420 for passenger side, 0430 driver side). I can tell you what you need to do to get it inspected, if that becomes an issue.

I think you said you kept cats on the car with your LTs.

There's a little "special modification" I was going to do to prevent this from happening (sorry, I wont post it publicly). Some of us can't modify the tune to turn the rear O2 sensors off. But if you can, then turning off the rear sensors will prevent those codes from showing up.

For those of you able to read OBDII data, if you look at mode 6 pids 21 and 22, they contain the data and thresholds related to this issue. During each driving cycle, a count of O2 cycles outside of limits is counted, in relation to the front O2 signal. If the amplitude is too large, the 'counts' increase. Then over a few driving cylces, the accumuated counts exceed the threshold limit, and the CEL is shown for it.

If those mode 6 counts can be adjusted in the tune to raise the thresholds to some very high value, I would like to know that for future reference and so it can be changed in my next tune.

Xeremeh

Mike,

I actually am running shorties on it, which is why I was abit confused because everything hooks up just fine and I haven't seen many problem with cats and shorties. I emailed brenspeed. I hope this is just a matter of fine-tuning the tune.

rdsx18

How long after the header/x-pipe install did this start happening?

Xeremeh

I did the header/xpipe install about 2 weeks before the tune. Then about a week after the tune, it started coming on.

rdsx18

Hmm, would high flow cats set off this code? Or maybe you need the 02 raisers that brenspeed sells? I'm not sure, but I am sure brenspeed can help you out. Awesome people over there.