SC w NO CATS and AFR gauge

[SouthShoreM3]

All,

So after a week of install I finally received my vehicle back with needed new power! I am very happy about this but have not tested its true capabilities. My questions are for those that are SCed and are running a no car setup and have used one of the secondary O2 sensors (bank 1) for the AFR, did you get an increased emissions or service engine soon light come on even with the necessary software specs in place?

If so how did you go about removing this light? I have been running a Dinan mid pipe for almost 3 years and the primary function of the their stage 2 software was to not have this light come on.

The code that comes up is in fact that sensor for bank 1, which where we put the AFR to read into the gauge of the inside.

Why is this all of a sudden now an issue? I have VF looking into it, but it seems like this should be something relatively harmless and the vehicle is 2010 E90 so it's not as though this is a brand new car.

Thanks in advance for any thoughts or advice on this. I would like to not go as far as wielding a bung (spelling sorry) and hope is a simple fix.

[m3an]

Are you using a wideband AFR gauge? If so aren't you using a separate dedicated o2 for the gauge?

[pbonsalb]

Secondary 02 may not be true WB02. They just tell whether the cat is working or not. Assuming you mean you have removed one of them and reused the exhaust bung for a real WB02 sensor for your gauge, and have a tune that is set up for no cats, you may still have a problem. I think the tunes simply alter the signal, but expect the heater circuit to work and the signal alteration is based on it being in the exhaust pipe. If so, you may have to add a third bung if this is the way you want to do it. Vibrant sells stainless bungs for about $5 and you can drill the pipe and mark it for another bung and take it to a welder.

The easiest thing to do would just be to read your primary 02, which are real WB02. There are a few ways to do this. Right through the OBD2 is one way. A piggyback is another way. I can read my factory WB02 right through my Vishnu tune, having it displayed on the cluster.

[SouthShoreM3]

Thanks so far for the responses. My gauges are all stack gauges and are mounted I to the ashtray set up. I keep clearing the code but it continues to pop up. The other bung is definitely an option, however I live in MA and its a matter of finding and trusting someone to do that work.

I'm just curious as to why these secondary sensors are now picking this up as the Dinan software I had prior basically turned or tricked the computer to ignore these secondary sensors. Unless software parameters have changed with the SC tuners out there, but from what I have tea it seems like a lot of other members that have gone this route use the same set up and location for their AfR location and reading output.

[pbonsalb]

The software may not have turned them off. Call Dinan and ask if you can remove both rear 02 and plug the bungs. They will probably say no, but I am not certain.

[BPMSport]

OP: I'm a little lost reading your post... but I'll chime in based on what I see..

There are a bunch of different ways to deal with the rear o2 sensors. They can be turned off which leaves catalyst monitoring in an unready state, or changes can be made to leave these monitors in a pending state. The other way of doing it would be to remove faults associated with them, which would leave them functioning but not throwing a SES light on the dash.

Now, I do have a few clients that have NO post cat o2 sensors at all. And as pbonsalb said, even with the rear o2's turned off, the car is still looking for the heater circuit and will throw an additional fault if the sensors are unplugged.

If you look closely here: http://www.m3post.com/forums/showthr...t=dinan+teaser - you'll see that the OP does not have any post cat o2 sensors installed at all.

http://www.m3post.com/forums/showpos...5&postcount=60

When I tuned his car, he told me that he had no plans of putting in the post cat o2 sensors, so I modified the code properly in his car to ignore the rear o2's as well as the heater circuit it's looking for. You can certainly use your own wideband sensor there where the stock post cat o2 sensors are - without errors - that way you won't need to weld in an additional bung. You'll just need a calibration that is set up in that regard, very easy to do.

The best thing to do is to see what faults the car is throwing, and if it is infact the heater circuit for the rear o2 sensors, either replace them or have a competent tuner modify the file to ignore monitoring of that circuit.

I hope this helps.

[SouthShoreM3]

Thanks Mike. So over the last few days it seems the issue is the AFR SENSOR that is in the secondary O2.

In going to weld an extra bung Over the weekend and this should clear things up...hopefully.

Could also be why the AFR is not getting a consistent reading all the time.

[SouthShoreM3]

So a few days ago all of a sudden the AFR gauge just stopped working. I'm at a place this morning that can weld a bung so I am hoping that this should be the safest and correct solution to the problem.

Weird how the gauge stopped working as the other two are in fine function.

Curious as to what other get for reading on oil pressure at idle and and with throttle half engaged. Mine typically stays at a steady 80psi but will fluctuate back. Te weird thing is when I turn the car off the oil pressure gauge stays around 40?? I would assume that it would go to 0 with the vehicle off

[SouthShoreM3]

Resolved...fuse blown