I was just looking at this post http://www.contour.org/forums/ultimatebb.php?ubb=get_topic;f=6;t=003629
My questions about this are: With the exhaust mods I have, especially the Y-Pipe, do I have these Cat's on my car still? Also, how hard is it to take the Cat's from that post off the car to gut them, cause like Brad said, why chance it? Finally, I dont have the money for dyno or Apexi, but will I be running too lean with all the 'opening up' of my breathing systems? If so, how bad do you think it would be for the life of my engine? I want more power, but not at the expense of my engine's life! Thanks for the help! -Nick

YEs you have the precats, they only go bye-bye's if you buy headers.
And the precats are a biatch to remove, hence why we gut them in situ.
If you hook up a shop vac to the front precat while you are gutting it, it'll suck all the nasty dust out, so you will be ok.

Still not worth it to chance it to do it on the car, Terry's words, not mine. Even with the vacuum it will blow around enough to get back into an open set of valves. I use the same method when I gut them on my bench and there's always some that poofs out when the top is broken though... Maybe it'll take video proof for you to realize...

Nick, engine life should not be effected with this mod so long as you get a good set of MIL eliminators.

Im not denying you Brad, Im sure there is dust that comes out still with the shop vac, but this is the first time that anyone has mentioned using a vac while on the car. Brad, could you tell me how to get them off my car so I can do this on my bench too? What about the engine running lean with all my other mods? And finally, what is with these "Mil" eliminators, I have never heard of them, although I can assume what they do, is there a place that explains how they work, and where I purchase them (if indeed I purchase them and not do it myself) thanks for your help guys!!!!! -Nick

Actually, using a vacuum on the end of the front pipe is a trick that goes back almost as far as the mod itself. I started using it to cut down on the dust I breath while doing the mod on my bench which is where I noticed the dust still coming out of the head flange end.

To get the front one off is easy, a deep socket and some amount of patience works well. The rear one is the bear to learn. An assembly of 10" extensions, a swivel joint, and a deep socket makes things work pretty good. Using the 30 or so inch assembly, go from the rear of the car, abover the steering rack, with the ratchet about where the cat goes. It's the straightest and easiest path I've found to removing the rear one.

Gutting the cats will not change the air/fuel mixture, so you shouldn't have to worry about running lean. The PCM compensates pretty well for most of the basic mods because the MAF remains directly in the intake path keeping track of how much air your motor is eating up. You will need MIL eliminators for the downstream sensors because there will be no difference from the upstream sensor and the computer will figure out that the pre-cat isn't doing it's thing and set the CEL. I think a couple guys sell them or there is a mustang site that has links to a supplier. Try a search for MIL and you'll get lots of info.

My engine runs lean after the mystery mod, so I am buying bnoon's 19lb injectors. Check it with a datalogger.

I have the directions for the MIL eliminators.
$7 in parts from Radio Shack.
Send me an email and I can get it to you.

FWIW, I did the front cat gut on a bench, but the back cat gut in situ.

We have very similar if not identical mods, 160 hp and 157 tq on my Non-SVT. You should be about the same.

My Cougar also runs lean with my combination of modifications...and I am also getting 19lb injectors to compensate for this.

I've logged my car a bit and I find it actually only runs lean at or near WOT. Seems the PCM can keep up for anything else...

This seems to make sense for any non-SVT engine with bolt-on modifications, intakes, gutted precats, SVT UIM/TB. Ford would not have spent the money on 19lb injectors if it didn't have to to produce the extra HP out of an SVT engine. So if your dynoing anything above probably 185 fwhp (close enough to early SVT 192fwhp) than 19lb injectors are probably a good thing. And +15HP is not unresonable with a few bolts ons...

I have yet another question... If I use the MIL eliminator on the O2 sensors, wouldnt that make my ECM not able to change mixture? I know tw0wheelin said that it would not run lean from the cats gutted, I was thinking about it running lean from using the MIL eliminator?
I thought that the ECM uses, among many other things, the O2 sensors to know if its running rich or lean and to compensate different running conditions by using the O2 sensors? If the O2 sensors are sending the same voltage, then wouldnt the computer not know that they are running lean? I am more worried about my engine killing itself, for the couple of horsies I would get by doing this. Thanks for all the help so far guys!! -Nick

I'm sure someone who actually knows more about the MIL eliminators can give a better answer than this, but the main concern from the computers point of view is if the second o2 sensor is moving or not. The front one should be moving quite a bit, the second one should be barely moving, as long as the MIL eliminators keep the second (downstream) sensor fairly idle and stable, all should be good. Anyone who has better info on how the MIL eliminators work is welcome to correct me if I'm wrong, just recalling what I learned in my auto classes a couple years back.

Aussie, Could we get those directions for MILs put up on the How-to page?

Thanks,
--Matt

Heres a link for the MIL Eliminators that I plan on using... http://www.zx2racing.com/mods/mods_mil.htm
-Nick

Now, just one more question... How many Eliminators do I need? Just the downstream sensor, which there is only 1 of, correct??? Thanks... -Nick

One downstream sensor on each 'bank', so you need two for a V6.

Hmmm.... Maybe mine is running lean with all the mods I've done? Can anyone tell me if a dyno session with an OBD1 'tour will be able to measure this? Also, how do you dyno an ATX? (Leave it in 1? 2? OD off? )