Your mileage probably won't change unless your cats are seriously plugged.

 

Same here. 17 - 18. And it is incorrect. Mathematically upon fill ups I avg about 14 - 15mpg. The little edge calculator is not accurate at all, unless you reset it on a highway trip. Then it usually stays quite close to accurate.

 

I have it on level 1, adjusted for tire size, and it says 18.4mpg and when I manually did it, it said 17.9.

 

Just another thing. I had been asked why I didn't do a direct replacement. The guys at the shop said it would be better to delete 4 cats and go with 2 universals because a lot of times, the downstream cat has issues if you replace just the one that is bad.

 

That's strange, because it's the absolute opposite. It's been proven over and over again. But there's a reason. For 1, it's not cat issues. Keeping all four and just replacing the bad keeps you right in the center of margins within programmed parameters. Replacing the 4 with two universals pushes you closer to the outside of margins within parameters. That means that that particular install has to tight or you could get a CEL. Meaning it can't leak within the Y and before the downstream O2 sensors.

IF there welds leak and they very easily can because Ford uses a grade of stainless steel in the Y, I know, I've welded them and you get a better weld with Tig or Mig stainless wire/purge method. My cats are custom flanged and welded directly to the header collectors. Anyway, many shops use fluxcore or solid steel wire to Mig which is how you can end up with problems. They leak!

 

Ok, but you have been telling me the whole time that going the route I went was going to be fine. Now you are just telling me this?!?!?! I asked you if I should do a direct replacement. Then when I told you why the guy said don't do a direct replacement, you told me to post it on the forum. So I posted it and you are telling me that I just created another problem by ordering the universals to be put on. I am trying to get rid of the codes! Not cause more. I don't have 2000 bucks to throw into factory replacements and I didn't know that just replacing the one cat would be ok because everyone was saying that I would be fine if I replaced the 4 with 2 universals!!!!!!

This is exactly what your reply was to me asking about replacing 4 with 2.

"Yep, - Two Magnaflow converters w/O2 bungs, because they're OX compliant.

Take your old converters to the scrap yard. That WILL wash the cost of your new converters. Some have even made a little money doing so. Scrap price for the old parts are about $200.
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Now, all you'll have to do is pay an exhaust shop to install. Do it this way and you'll save more than you originally though.

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With that, you can afford a new Borla Muffler. A little pricey, but worth it.

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When finished, you'll have nice deep throaty growl, better performance and NO CEL."

 

Exactly! What the Frank is wrong with that??? I can't help it if you have a hard time understanding, but don't get cheesed at me for that!

I gave you correct information! So buzz off..

 

If the exhaust shop is incompetent, what the hell am I suppose to do about it???

 

The exhaust shop is the best around Indianapolis. Were u just saying thàt if the f it up, then it will be an issue? I thought u were saying I should just replace just that cat? I guess I'm just confused as to what advice u were giving... I thought u said what I was doing would work fine given the shop making good welds. I took your advice cause I know u know your ****.

 

Yes, - it revolves around whether it leaks or not. If they replace one of the four, they may get away with a little leak or two. But if they use two in place of four, they may not get away with that.

So when they said , - it doesn't make sense because using just two works perfectly, but ONLY IF there isn't a leak within the Y before the sensor that determines efficiency (the downstream O2 sensor).

Ford sorta over does with there converters by using 4, but that is what they program to. Therefore it's those parameter margins you have to stay within in order not to get a efficiency CEL. Using two to replace is fine as long as you use O2 compliant converters. With that, your efficiency parameter is pushed to one side of the margin or closer to CEL you could say. So if they do a half *** job, you could get a CEL.

Either replacing just the bad one or replacing them all with two works. For the price they gave you, replacing them all for two new converters is good. However, the info they gave you is *** backward. Which means they would rather replace them all, which is fine IMO. What's confusing things is the BS info they gave you for doing so.

Like I said, when it's warranty work, Ford takes the cheapest rout of course and just replaces what's bad.

Make sense?

 

Yea that makes more sense. Thanks. I found another shop called heaven bound customs and they do a lot of performance work and specialize in custom exhaust work. I think I might have a chat with them to get a feel for their ability to do this right.