Anyway to get rid of CEL from going catless?
 

I have a full 3" custom exhaust. Resonated midpipe, and no mufflers. Of course, its going to throw a CEL, and so far, theres no way to avoid it, but is it possible that after a "tune" it can get rid of the CEL? Or is my only option to suck it up and live with the CEL?

I've read that the RP Supercat gets rid of the CEL, the newer versions, but again, I'm on a budget right now, and its supposedly better gains for the car without it anyway? I hear after some time though, the CEL does come on regardless. Any opinions guys?

P.S. - And yes, I have thought about disconnecting the CEL bulb, but again, I dont want to risk a REAL problem with the car, as its pretty brand new.

P.P.S. - I heard from SOME people, mainly the mechanic who was going to install the exhaust for me that if we remove the cat, itll send hundreds of problems to the ECU, and cause nothing but problems to my car, and since its brand new, its not worth it. Then I've heard from people who have driven rotarys their whole life, and the better airflow and less restriction, the better. I have a friend with a 7, who has a custom midpipe going from 5" to 6" back to 5", without problems. So can anyone clear this up for me? Is it harmful?

Not harmful at all, just annoying.

My StealthTL Hi-Flo™ cat just burned out due to 3k miles with the Racing Beat flash vaporizing it's coating.

So I've become used to seeing the code every day.

S

Yeah, guess he got lazy and told me that to scare me off heh. I figured all it can do is good, its just an annoying light that I've had on my last car for a year or so, due to actual problems, so I'm sick of seeing it

when i removed my cat on a different car i used a eleiminator plug that tricks the voltages of the o2 sensor that had to be removed.... otherwise with the cel on i was getting piss poor gas milage

Yeah, unfortunately the eliminator circuits won't work on the '8.

S

well you can always drill ahole and weld a bung to insert the o2 sensor or get a re-flash of the ecu which removes the sensor check?

NO CAT = CEL...

Period...ALWAYS...no way around it...

Get a snail...thats a better solution...

I have the 02 sensor installed on the midpipe...and while occasionally (weather is right, jupiter is in the right positon) the CEL will disappear...it will always return...ALWAYS...

well im buying a midpipe soon, so i think im goona buy a CEL scanner so i can check my car once a week and make sure nothing is really wrong. but stealth, have you ever had a 02 sensor burn out cause of the heat from the race flash?

Yeah, I have the o2 bung already on my pipe as well. Why do our damn cars have to have this annoying feature where NOTHING can solve the CEL problem ;) I always thought you can just clear it with a scanner, is that not possible with any car? And wouldnt this mean I'd be getting poor gas mileage regardless then?

The car is using the sensor to calculate values to operate the car, and to ensure nothing is amiss...all cars do this same function...

You can clear it...but it will come back...

Your going to get craptacular MPG regardless...with or without the cat...

Does this also void mazda warrantys? Can't they go through the ECU and find out when and if the cat was removed?

I have gone catless, if cel comes I will get a scangauge ii to clear it and also monitor my car. From what I heard some people say that the non-fouler trick may keep the cel away but not for long...

You WON'T get any worse gas mileage without the cat.

The second sensor ONLY monitors the cat. It's the primary one that would hoop you.

I have a Scangauge II hooked up all the time for the temperature functions, so anytime I want I can reset the code, light goes out, but it will come back tomorrow so why bother.

If you slide the original cat back on and reset, the only info the dealer could read is the date of the last reset. "Yesterday" might set off some suspicions.....

S

Depends on what you need warrantied...

But...always put it back in before going back to the dealer...its literally a 20 minute job with hand tools...

And do the ECU reset...

What those people are seeing is NOT the fouler thing working...

It takes a little while after an ECU reset for the tables to build and the computer to determine that something is wrong...

The fouler things DO NOT WORK...

I see. Thanks guys. And theres no way to slide my exhaust on the stock cat, since obviously my piping is bigger then the stock cat piping.

I disconnected the battery to work on the car...It's a bad habit and I'm sure I do not have to...but this one time at band camp on my old car...I dropped a screwdriver while checking my air filter and it hit something and shorted out something and a few fuses blew...so now I just do it all the time...

I have a nice round black sticker for you :)

So I guess I should invest in a RP supercat. Should rarely throw a code, yea?

well if you want to get the RB race flash, dont get the supercat, thats what im doing, so i need the midpipe

So what you are saying is, I can keep my midpipe, as long as I:

a. deal witht he CEL
b. get a supercat.
c. get the RB race flash?

I thought THE only way to get rid of it is what twinkie said. Gotta hit FI and get a tune up, or get a supercat.

Sorry to resurrect an ancient thread but my particular variant to this question isn't fully answered...

I understand a CEL will be present, I have a local shop doin ga full catback for me with cat delete and resonated interior, 300 bucks with dual magnaflow mufflers, parts install included... can't really beat that right? It'll also have a bung for my O2 sensor..

my question is:

Do we have proven gains in power? Any fluctuation in fuel economy up or down? What detrimental side effects may occur to the vehicle short and long term if any? From what I gather it's a mere monitor for the cat system, does it adjust the F/A mix like the upstream???

Thank you for your time.

the only power you get from an exhaust system is by losing the cat. it will give you a cel (almost always) but wont hurt anything. you can mask the cel with tuning software like a cobb, mazdaedit or adptronic etc

These questions are answered in a million other threads, much more recent than this one. Read the new owners and modding for newbies stickies.

The rear sensor is for monitoring the condition of the cat (or lack thereof).