Catalyst System Efficiency Below Threshold (Bank 2).

inurok · #1 11-09-2006, 09:58 PM

I get a check engine light every once and a while. I used my edge code reader and it states "Catalyst System Efficiency Below Threshold (Bank 2)"

From what I read this means either bad 02 sensor etc? My truck only has 12,000 miles on it and had the Roush Intercooled SC installed about 1,500 miles ago.

IS there something I can pour in the tank to clean the 02 sensors and such?

Thanks you in advance.

justjames80 · #2 11-09-2006, 10:23 PM

Could be a bad O2 or a bad catalyst. If the O2 sensor has been poisoned somehow then you are out of luck....just have to replace it. If the catalyst has become clogged or damaged then you might want to consider a set of highflow cats and maybe a tune to delete the rear O2's from the computer. That way you can still pass emissions (visually or sniffed if you have to do those) and you won't get MIL's.

inurok · #3 11-09-2006, 10:33 PM

Quote:

Originally Posted by justjames80

Could be a bad O2 or a bad catalyst. If the O2 sensor has been poisoned somehow then you are out of luck....just have to replace it. If the catalyst has become clogged or damaged then you might want to consider a set of highflow cats and maybe a tune to delete the rear O2's from the computer. That way you can still pass emissions (visually or sniffed if you have to do those) and you won't get MIL's.

Thanks. IS there a way I can change these O2 sensors myself? Where are they located?

Thanks

justjames80 · #4 11-10-2006, 01:36 AM

Easy to find...just look at the exhaust piping. The one you are looking for should be the passenger side O2 sensor furthest towards the back of the truck. It is a round sensor with a wiring harness attached to it. Should be able to just unplug the harness from the rest of the vehicle then unscrew the sensor from the exhaust bung. You can either use a crescent wrench or a ratchet with a O2 sensor socket. Might want to put a little penetrating oil (PB Blaster, Aerokroil, etc.) on it first. They usually run about $50. I would test the sensors and the cats first with a DVOM...just to be sure it actually was the O2 sensor at fault. An exhaust leak would also cause the P0430 code.

Of course emissions related components are warrantied for longer than powertrain warranties. Might want to let the dealership check it out.