I've been spending some time working on the O2 sensor routine. I'm actually trying to adapt the electronics of the ECU to use a wideband instead of the factory narrowband sensor. I've found something in the ECU where it appears to use the long term fuel trim even when in open loop mode. I've suspected this for a long time but this is the first time I've seen confirmation of it in the code.

This also explains why a piggyback tuned car will have good AFRs on the dyno but then a week later they're nowhere near what they were tuned to. I ran into this same problem when I designed a piggyback for the ralliart last year.

One other point, the routine is different according to the year. I haven't spent the time to figure out what the differences are but it was definitely changed for the '06 model.

-Michael

 

Hackish what you are saying is that when you actually implement the ECU to read the wideband , we can use a regular BOSCH LSU wideband and the ECU will be able to read the a/f more precisely. Now this is VERY INTERESTING , my bro who is a HONDA FAN has told me that 2000+ hondas have this type of setup from the factory ECU's , apparently that's why they can actually have a nice MPG while having a great performance when WOT. He had a disasembled board out of a RSX and showed me were the input of the stock O2 sensor was going, it has like a separate very small circuit inside the ECU box. If you somehow pull this it will be a must for daily driving because the actual reading from this Wideband can provide better ratios while cruising, not to mention we can actually datalog everything @ the dyno without having to buy expensive widebands.

Nice find !!, I am still setting up a group buy here in PR I got your number and will call you soon.

 

Not exactly... The intent is to allow an aftermarket wideband such as the innovate LC1 to feed the factory ECU.

MY2000+ hondas have a 4 wire heated narrowband sensor. No wideband at all.

Widebands these days are not expensive at all. I think I paid about $200 for my LC1. Now my Horiba... that's another story...

-Michael