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Discussion Starter · #1 · (Edited)
Ever since I swapped over to the off-road H, it has been really noticeable that the car is running rich. We're not talking the typical exhaust smell that you get when you're running a catless mid-pipe...it's really rich and seems to be getting worse. I'm not sure if it has been this way ever since I started running my Brenspeed tune and the cats were burning most of it off, or if it has just started. I met up with my brother last night who is a Ford master tech and he was amazed at how bad it was.

I emailed Brenspeed this morning and told them what was going on and asked if I could email them a data-log and have them take care of any adjustments that need to be made. This is the response that I got:

I am certain the car is NOT running rich. All AF adjustments are made and controlled by the ECM based off of O2 sensor readings. Eliminating the catts will cause the emissions of the car to be much more easily smelled. The catts are in place to filter out those things and when you remove them all the emissions are just sent straight out the tailpipes. A/F is completely dictated through the ECM and makes it's own adjustments based on the O2 sensor readings.

Any suggestions? If this is the case I'm assuming that I should try cleaning up the MAF sensor and resetting the computer.
 

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MM's Resident Muffler Shop
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Thats the same damn response I got last week when I told them my car smelled like it was running really rich. My friend is running an O/R mid w/ ford tune and his doesn't smell damn near as rich as mine. After that response I chalked it up to him having mufflers and me not. But maybe its they're tune and they just don't want to go through the trouble of re-writting it?
 

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Everytime I pull into Ford, the service managers office is right next to where you pull in and he says that my car stinks up his office. It will always smell rich with the O/R pipes. And yes, A/F is dictated by the front O2's and ECM and will not change with removing the cats. If you have driven older cars from the late 60's, they all smell like that. I'm not saying that the Brenspeed tune is not richer than the tune you had before, it may be. Try loading your old tune and see what it smells like. I think you will find it will be the same.
 

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MM's Resident Muffler Shop
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I didn't have a tune before running the O/R X (ran it for about a month) and there was a HUGE change in the smell
 

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Discussion Starter · #7 · (Edited)
Thanks guys. I've been around plenty off cars with off-road mid pipes before and never smelled anything remotely as bad as this. I may put the stock airbox back on and reload the stock tune to just see what it's like with the off-road H. I'm assuming that if it was my upstream 02 sensor, I would be throwing a CEL right?
 

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MM's Resident Muffler Shop
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No, but my exhaust tips went from clean to black w/in a week. And yes I know they're going to turn black by running an O/R midpipe. But w/in a week?
 

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Discussion Starter · #9 ·
I always laugh when people say it smells rich. haha. What are the fuel trims? does it blow black smoke?
I haven't data logged it and this will be my first time trying. And yes...there is visible smoke anytime you rev it from a standstill. It smells exactly like a carbureted engine with a piss poor fuel adjustment. Like I said, I've been around off-road mid pipes before...this isn't the same.
 

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some one needs to get a wideband and determine if it IS running rich... black tail pipes and like trick said black smoke are indicators, but proof is that the thing is sitting there idling at 12:1 or some craziness.. if it is, then I would call brenspeed and tell them to shove the tune up there ass and get your money back. its wrong to sell jacked up "tunes"
 

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Discussion Starter · #12 · (Edited)
well if you get smoke you are dipping under 10:1 and thats not good!
There's a decent amount of visible exhaust but I'm sure most of it is a combination of the low temps and high moisture that we've had around here the last few days. It's not thick black smoke or anything though...
 

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I'd be willing to bet his o2's stay at 950mv's
 

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Luke - you mentioned reinstalling your stock airbox and reloading your stock tune. If your rear O2's are still gone, you won't hardly be able to get it to idle.
 

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Discussion Starter · #16 ·
Luke - you mentioned reinstalling your stock airbox and reloading your stock tune. If your rear O2's are still gone, you won't hardly be able to get it to idle.
Thanks Boogie. Not sure why I didn't think of that. My brain's not working too well lately...
 

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Don't worry - I did exactly that on Saturday. I reloaded the wrong tune (stock) while trying to track down a problem, and it barely idled. I looked at the wideband and it was going from 10.0 to 20.0. Sounded like it had some monster cams in it!
 

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Luke - you mentioned reinstalling your stock airbox and reloading your stock tune. If your rear O2's are still gone, you won't hardly be able to get it to idle.
Don't worry - I did exactly that on Saturday. I reloaded the wrong tune (stock) while trying to track down a problem, and it barely idled. I looked at the wideband and it was going from 10.0 to 20.0. Sounded like it had some monster cams in it!
Having or not having rear O2's will not make any difference in how your car idles or runs. The front O2's are what determine your your fuel trim and A/F ratio. The rear O2's are there for one, and only one reason, to let you know that your cats are working properly. The computer is looking for a different reading from the front sensors and the rear sensors, and that is all.

When I went to my O/R mid-pipe I ran the same tune as before the install for two weeks before I received my tune to turn off the rears so that I wouldn't throw a CEL. Throwing a CEL for rear O2's is nothing more than an annoyance. You could run forever with that CEL popping up.
 

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Hey coolhand, I ran an O/R X pipe for years before I had my car tuned and the difference in smell from the catted was definitely noticeable but I expected this and you probably did too. But then when I installed my intake and loaded up my tune, there was another big difference in smell (like it was running really rich). I brought it to my buddy up at ford for his take on this; after he ran it and looked it over he said that everything was fine and that this was to be expected because my car was now running a tune that was for 93 octane with the X pipe.

If you doubt yourself. Install a new spark plug and then in a week or two see how much carbon buildup is on it. Also the rear O2 sensors are useless at this point, think of them as paper weights that leave you with an annoying light on your dash (before tune)
 

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I've had my o/r pypes X midpipe on mine for quite a few months now. Service engine soon light has been on since I put them on. Haven't had it tuned yet and the smell is noticeable but not excessive. Car IS running a little rich - I had it on the dyno a couple months back for a base run just to see what she was making. So from the sounds of things...getting rid of the catalytic converters will make them run a little rich.
 
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