Weird Afr's After 02 Spacer

[bdelaney4000]

That I'm not sure on - I know the secondary o2 sensor is capable of throwing codes for multiple items including catalyst efficiency, rich or lean codes, and sensor failure. The primary O2 sensor on the turbo is more expensive than the secondary so I would assume it has more capability. However, without seeing exactly what parameters are monitored by each it's hard to say either way.

 

[777-300ER]

That I'm not sure on - I know the secondary o2 sensor is capable of throwing codes for multiple items including catalyst efficiency, rich or lean codes, and sensor failure. The primary O2 sensor on the turbo is more expensive than the secondary so I would assume it has more capability. However, without seeing exactly what parameters are monitored by each it's hard to say either way.

The sensor does not throw the code, the ecm interprets the data that the sensor creates and decides if there is a problem or not. Catalyst efficiency measures the change in AFR after the catalyst to see if hydrocarbons are correctly being removed from the exhaust. Rich to lean means that the catalyst is working correctly, but the sensor is seeing readings much too slowly compaired to the 1st sensor. Sensor failure is either a short in the sensor, or the sensor flipping wildly between two voltages.

 

[bdelaney4000]

The sensor does not throw the code, the ecm interprets the data that the sensor creates and decides if there is a problem or not. Catalyst efficiency measures the change in AFR after the catalyst to see if hydrocarbons are correctly being removed from the exhaust. Rich to lean means that the catalyst is working correctly, but the sensor is seeing readings much too slowly compared to the 1st sensor. Sensor failure is either a short in the sensor, or the sensor flipping wildly between two voltages.

Obviously the sensor doesn't throw the codes...I was speaking in layman's terms .

 

[Stija]

Most stage 2 tunes patch the emissions code so you don't get a check engine light. The problem with that is then the sensor doesn't show readiness. Flashing back to stock allows readiness to be reset, but you need either a really good cat or a good spacer setup so you don't throw codes for catalyst efficiency.

Dumb Subarus still show readiness, just checked mine yesterday. Only egr was not ready cuz its unplugged and turned off w tune.

I am surprised by the advanced technology VW uses that doesnt allow for turning sensor off and unplugging it if need be. (Mines still connected but turned off in tune.) Catalyst and all other monitors ready. Sometime it pays to have a dumb ecu.

 

[bdelaney4000]

Dumb Subarus still show readiness, just checked mine yesterday. Only egr was not ready cuz its unplugged and turned off w tune.

I am surprised by the advanced technology VW uses that doesnt allow for turning sensor off and unplugging it if need be. (Mines still connected but turned off in tune.) Catalyst and all other monitors ready. Sometime it pays to have a dumb ecu.

Some of this depends on which state you live in. From my understanding some states allow you to pass OBDII readiness check with one readiness monitor showing not ready/not passed. I live in NH and everything must be ready hence why I have to flash to stock every year.

 

[Stija]

Yea everything must be ready in az too which is why i was checking it the other day before a reflash w another map, and hence a reset.

All were ready but egr not ready. Egr is unplugged but on the car. So i could plug back and ask for an emission map mod for egr on. When time comes..

 

[jimlloyd40]

Yea everything must be ready in az too which is why i was checking it the other day before a reflash w another map, and hence a reset.

All were ready but egr not ready. Egr is unplugged but on the car. So i could plug back and ask for an emission map mod for egr on. When time comes..

Or you could just get a new car when it's time to be tested. JK ?