AFR bung installation stock exhaust, Looking for where to install the exhaust bung on stock 2.0 Options

[nditiz1]

I'll be getting my new AFR in a few days and have the stock 2.0 exhaust Liestriz. There is no 4 to 1 collector like on an extractor muffler. Can someone give me advice where to install the sensor mount? Do I need to cut a hole in the muffler? Thanks.

[Olympic 914]

I thought that closer to the head was ideal. but that would mean putting it in the HE before the shrouding for the heater. On my motorcycle it is placed about 4 inches from the exhaust port.

that said, currently the sensor on my car is mounted in the Triad exhaust, probably more than 3 feet from the head. and it is a heated sensor. I have always wondered if the distance from the head could affect the accuracy of the sensor.

[jd74914]

I used to say it could be put into the tail pipe, but I was wrong, you run a good chance that the sensor will not heat up enough to give accurate readings. A heated sensor doesn't provide enough heat for an accurate reading, it only speeds up the sensor warm-up cycle.

There is no magic distance from the head. In general, hotter is better, until you exceed 1030C (1886F) if you are using a Bosch LSU4.2/LSU4.9 sensor. I believe the NTK sensors go a bit higher but they aren't super common in the hobbyist market. Distance from the head is important to reduce sensor latency (delay time from reading what's actually happening) if you are doing per cycle tuning, but that's an OEM kind of thing.

The heater is capable of keeping the Nernst cell hot enough wherever you put it really. The issue with putting it into a tailpipe is flow reversion pulling fresh air in and causing the sensor to read false lean.

It may take a while for the sensor to heat up to the point where it gives a good reading; a heated sensor can help with that.

Pretty much all sensors/aftermarket controllers these days are heated and use the elements so you don't really have to worry about that. (IMG:style_emoticons/default/smile.gif) Heating times are in the 30 to 60 second range with a decent controller.

that said, currently the sensor on my car is mounted in the Triad exhaust, probably more than 3 feet from the head. and it is a heated sensor. I have always wondered if the distance from the head could affect the accuracy of the sensor.

I would get a muffler with collector too and put it there if you can so you can read all cylinders. Otherwise it seems like in any of the HEX pipes like DD said would work OK, just not give you a full picture.