Just wondering about Catatilitc Converters
 

Quick question,

When I got my mustang (87 GT) all the catalitic converters were cut out and replaced with straight pipe. What are the plusses and minuses to doing this? Once in a while my engine light will flash on and I'm wondering if it's due to the emissions not being properly regulated. Should I get a new H-pipe?

CapaC

Have you had the EGR recall taken care of? Might Check Engine light actually burned out because of that stupid problem. Still haven't had it fixed...

The recall fixes a wire harness that prevented the computer from reading the EGR valve position. Don't know if that applies to your year, though.

Rich D.

Thanks!
 

Hey thanks for the heads up on the recall. I knew nothing about it. The previous owner of my car did a lot of work to it but I am definately still going to research that recall and have it looked at.

No cats shouldnt effect your computer since the last sensors the computer sees are the O2s in the pipes and those come before the cats... I pulled my cats and it made my car louder but hasnt affected anything else, cept maybe HP.. but I cant really tell that for sure.. sounds cool though
-as

By removing the catalytic converters you decrease resistance in the exhaust track. This will free you up a little horsepower, but won't really be appreciated until you have augmented the remainder of your setup (TB, MAF, heads, intake, etc).

In the short, cats aren't going to effect you negatively, and might actually help just a bit. However, if you have to pass emissions, you won't be able to pass a visual inspection. However, I don't know anything about Canada's emissions laws.

On my car, I cut the heat sheilds off, cut a hole in the converter housing, pulled out the packing, and welded it all back up including the heat shields. Also, all cuts were made on the side that is up against the car and hidden by the heat shields. Visual isn't a problem, but I wouldn't have a prayer in a sniffer test.

--nathan

Freedom
 

Emissions are not a problem where I live. Canadian emissions are accually regulated by the provinces. Alberta has no emissions checking. However if I were to live 30 minutes west (British Columbia) I'd be in need of a new exhaust.

I do plan on putting in a new cold air intake as well. Any suggestions?

TB?
MAF?

:confused:

I'd suggest a Moroso kit, or some other fenderwell kit (C&L or Mac make them...don't have any experience with those). I'm not a big "ram air" kit fan. The intake scoop can suck up debri, or worse, water.

A larger TB will give you a little now, and much more later if you ever get deeper into the engine. I would go for a 65mm.

Is your stang speed density? Don't know about SD mods, but for MAF, a 76mm meter is what I run.

--nathan

Same here. My car is loud as hell.

Smogs are a biatch though.. I have to pay a nice chunk of cash to have someone pass it for me.

You're lucky you dont have that problem where you live. (Canada)

Trying not to sound like a moron (I'm really not I'm just beginning to get into this) but all I know is that my car is 99% stock and it's an 87 GT 5.0HO. I have no idea what the difference between speed density and MAF, or even what MAF stands for. Same goes for TB.

*goes and hides in a corner*

I just learned this the other day...
 

Does your car have one of these?

http://home.earthlink.net/~cvecchio8...ages/Dx-02.jpg

Then its MAF (Mass Air Flow). :D

If you mean the little black chip, yes...yes it does.


BTW-That is a very sharp looking engine. Hope mine looks that nice one day.

lol.. yes its a nice engine. I wish I could say it was mine.. just an example. ;)

Mine's totally stock. :mad: I love it though.. it purrrrrrrrrrrrrs.

If your car is stock then you have speed density. Fuel injected 5.0's had speed density from '86-'88 and switched to MAF for all '89+ cars. The type of setup you have relays the speed and density of the incoming air to the computer, while a Mass Air Flow meter (MAF) measures the actual mass flow rate of the air coming into the intake. MAF allows the computer to adjust for mods better than speed density, although BONE STOCK vs. BONE STOCK speed density cars are generally a hair quicker (only a tenth or two difference at most in a 1/4 mile).

Hmm I'm confused then. I have an '88.. its pretty much all stock.. but it has the black thing between the air filter and the TB as shown in the pic. Doesnt that mean its Mass air flow? :confused:

I thought you either had one or the other.. not both.

Is your car a Cali car? Mustangs sold in California were introduced to Mass air in 88 to meet the strict emissions laws there. Mass air was not used till 89 everywhere else.

Interesting! Yes I am in Cali.


Yeah dont get me started about our emissions laws :mad:
I'm surprised I havent gotten busted yet for having no cats for the last 8 years... :p

Re: Freedom
 

Actually, if you don't live in the lower mainland then you don't have emmissions testing. My car is plated for Kamloops so I don't have to get it aircared, and you can actually run a pre 88 car through the emisions testing without catalytic converters and using a few "tricks of the trade" these things can pass.

I live in MA and we have emissions testing here.... though the guy I used to go to didnt do any visual... though he closed down recently... wonder why? .... but I put on my OR H pipe, after I got my sticker... then I figure next year when it comes time again, i'll spend an afternoon putting the cat'ed pipes back on... or maybe try it once and see what happens.. if you dont pass you have like 30 days to fix the problem and retest
-as

In most inspection stations, when they see cars like ours come in, the first thing they do is look under for the cats. MA laws are strict but not too bad, I have had no problem passing. I do swap my h-pipe every year, but it doesn't take long and is fairly simple to do.

Confused
 

Well that's odd. Though I have no idea where my car originally came from (the previous owner found it in a scrap yard and fixed it up) it does have the black chip as well. Though I was told it was a hybrid and contained 88 parts as well as 87 parts. Hmm...