View Full Version : Exhaust code problems

07-31-2009, 07:47 PM
I just got the smog request and I have a 2 month old cel... so cleared the old codes the other day and this is what have came back up:

2 Faults Found:
16804 - Catalyst System: Bank 1: Efficiency Below Threshold
P0420 - 35-10 - - - Intermittent

16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
P0134 - 35-10 - - - Intermittent

Please say it is only the sensor that is worn not the cat also...

I have a 2.8l FWD so is this passengers side sensor by the cat?

07-31-2009, 08:10 PM
You need to replace the post-cat oxygen sensor on the passenger's side. I would deal with the Catalyctic Converter after that.

07-31-2009, 08:28 PM
Bank1 Sensor1 refers to the primary (pre-cat) O2 sensor.

Without the data from the primary O2 sensor, most car's will usually run a little rich for safety. If you fix the front sensor you might be able to get rid of the efficiency code for a little while longer. If not you can always try a spark plug non-fouler (CELiminator) on the rear sensor (b1 sensor 2) to see if that helps.

08-01-2009, 07:27 AM
Thanks guys! Sounds like a plan.

1. Change the primary sensor passengers side.
2. Clear codes.
3. If the cat code comes back, try defouler.

08-01-2009, 01:33 PM
Yeah, that sounds good. If it were me, I'd check the O2 sensor output in vag-com as well as the O2 sensor connector/wiring before I actually bought anything - just to be sure. I'm a cheapskate so I like to make sure there is absolutely no way to fix it for free before I actually spend any money.

Good Luck.