It's not a simple voltage yes/no that the ECU is looking for. It's more complicated than that, and a simple resistor won't work. You would just get a CEL for the ECU not seeing the O2 sensor operating correctly.

:biggthump

Mazdaedit personal - not to pricey

Yup, and just to add, the PCM does do random rich-lean tests to ensure that the o2 sensor isn't fouled. The result of this test cannot easily be replicated via a resistor.

Really, so its not a PWM waveform that the sensor sends to the PCM? And the PCM isn't looking for a difference voltage between the two O2 sensors or a difference in the measured data sent from the sensor and the data stored in memory?

It's looking for a difference, but it's not looking for a difference like how many pieces of fruit are present in each basket:
http://www.lulusoso.com/upload/20120...uit_Basket.jpg


It's sending specific information and expecting a specific response, more like this:
http://upload.wikimedia.org/wikipedi...er_(CATTC).jpg



Maybe those are exaggerated a bit, but should serve the purpose.

Obviously more costly than a resistor, but it works and you also get to tune your engine for more powahhh :)

FYI, the code that you will throw with a fouler is usually P0421 as opposed to P0420. Once the Rich-Lean test kicks in, it will detect that although the o2 is spaced out and seeing less concentration of emissions, the ratio doesn't match what the ECU is expecting.

P0420 ftw!

So...Is there no other option other than an approx. $470 MazdaEdit or repeated code clearing or black tape?

well based on your sig, you have a 2005, so the other option would be a COBB

Thanks for the tips/advise/patience!
So, please tell me about a "COBB". What is it? What does/can it do? Where can I get it? And approx. cost?

THX, again!

Thanks, P.S.
I checked out the COBB and for what I want, I feel it is a little rich for my blood. To clear the CEL code, I did try the battery disconnect trick accompanied w/ having the switch on and turning the lights on and leaving it for about 15 min. Hooked it all back up, started it and no CEL. I realize that this is temporary but for my present needs, it will work for me. I'm tracking it at the end of the month at Blackhawk Farms near South Beloit, Ill. I'll be taking along a spare coil, additional oil (and checking it after each session) and all the tools I can fit in the truck and on the trailer. It certainly has been educational and am certain will continue to be. Thanks to all for the help to-date.

MR Goodwrench...what group are you going to Blackhawk with? Might bring mine out too.

Moliver, I'm running w/ the Northwoods Shelby Club. Last I heard, they were filling up. Where are you out of? I'm in Green Bay. First tracked mine in May at Gingerman in South Haven, MI. Had a great time till I dropped a coil and slugged the Cat! Excited to get it back on the track. Been a great learning experience.

interesting..we never had a CEL on our S2 with the Bhr midpipe

it was the catted version though which i hear helps to mask the CEL a little more

erm ... a cat will prevent a CEL ....

Correct, you will not get the CEL for 'no cat' when you have a cat installed.

Help
 

I have a 2010 rx8. I'm getting the lean/rich error after installing a AP midpipe. So the Mazdaedit software with the Tactrix Openport 2.0 will kill my CEL?! If so I'll buy the software and device but I want to be sure someone has used this and passed an inspection. I live in NC and all they check for is codes. So someone please give me some good news on this. I've been searching and this would be better then buying a cat and playing swap out for a day or two a year.

Correct, MazdaEdit can turn off the ECU's ability to throw CEL codes. See this thread for more info: https://www.rx8club.com/series-i-eng...daedit-239275/

It's a long thread, but it's a lot of discussion about what you can do, what you can't, the development challenges, etc... If you are getting a MazdaEdit, I highly recommend you read the entire thread.

Yep, at least two of us have successfully done this on an s2, and there are probably several more out there. It's actually pretty easy once you get the software registered :)

https://www.rx8club.com/series-ii-en...5/#post4531808

Tuning the beast gets a little more involved...

So. Ahh.. I did it. I have mazdaedit and I think I killed my cel. Not sure if I'll pass emissions but hell its worth a shot. :) The advantage of tuning my car I believe will be pretty interesting. I have a lot of research to do as I'm pretty blind on using the program. I get the jist of everything but I'm not gonna start just changing values to see cause and effect. lol.

Wow you guys are life savers, I placed my order for the openport and now I dont have to explain to my girl every time the CEL comes back on that its nothing to worry about lol

If you don't mask out particular CEL, make sure you check your CEL from time to time to make sure it's not something else...