Exhaust question

[Bulldog Brewer]

Hello. I nee to have some exhaust work done . My cataletic converter is leaking and so is my muffler. Should I replace the converter or put a straight pippe where that goes? I dont want to lose any back pressure.

Thanks

The Bulldog

[Psychopete]

There isn't any difference in performance not having it. For emissions purposes, it might be a good idea to put the cat back on. Stinks really bad if you don't.

[EVH5150]

On my 2.9, it comes with the dual cat setup, now when I replace them, will I have to get two or can I get by with just one? What was the reason for the two cat setup anyhow. I just want to make sure that if I just put one cat on, I'll still pass emissions. I'm sorta tight on cash, so I dont want to spend more than I have to. Thanks

[Psychopete]

It's 2 cats in one piece. My Ranger came stock with no smog pump or EGR. I imagine the double cat was the only way to get all of the crap out of the exhaust to pass emissions...

Pete

[TheRangerOfDanger]

are you sure that there is two cats? sometimes one of those is a resonator, or a pre-muffler.
if there are two, are they in series, or is there one for each side of the exhaust piping before the piping joins? They often do the latter to help reduce backpressure
if you want to try, you might be able to replace one (the second one if they are in series would be best so that the new one gets already somewhat cleaned up air) and possibly pass. It's worth a shot cause it may save you some money, but it depends on how badly you are failing the test...

[EVH5150]

Thank's. Sorry I didn't explain it better, They're in series. Pretty sure it's two, one identical right behind the other. I think the first one is bad. I suppose I could replace both with just one and hope for the best. My truck doesn't go in for testing until next month, so I'll have time to fart around with it. Thanks for all your help

[TheRangerOfDanger]

Bulldog Brewer - if the leaks aren't from big holes, you may want to try to use some JB Weld to patch up the holes

EVH5150 - I would just replace the first one and then go for the test and see what happens... you might get lucky if they see that you still have the two cats and be more lenient. ON THE OTHER HAND, i wouldn't just replace the two cats with one. i'm not sure how the inspections work where you are, but I know in some states, if the vehicle came from the factory with two cats, it must still have 2 to pass

[Psychopete]

You didn't state what engine or what year. Mine is a 1988 Ranger 2.9L I have 2 cats but it's one piece. You can't just replace one. I bought a test pipe for it and elimnated the cat. (Both, 1 piece) I also put a dynomax super turbo dual outlet muffler on. You better be certain that this is not the case since they're in series.

J.B. Weld is the stuff. I swear, there isn't anything that stuff can't fix.

Pete

[EVH5150]

Originally Posted by Psychopete

You didn't state what engine or what year. Mine is a 1988 Ranger 2.9L I have 2 cats but it's one piece. You can't just replace one. I bought a test pipe for it and elimnated the cat. (Both, 1 piece) I also put a dynomax super turbo dual outlet muffler on. You better be certain that this is not the case since they're in series.

J.B. Weld is the stuff. I swear, there isn't anything that stuff can't fix.

Pete

1992 Ranger 2.9. Yeah mine's a one piece unit also. One question though. What's a test pipe? If it weren't for the damn emissions testing I'd get rid of my cats too. I have a Dynomax super turbo too. I like the tone it gives out. That is before my exhaust system went to hell! Lol.

[Psychopete]

It's just a strait pipe that hooks on to my headers. I welded it right to my muffler. Basically just elminated it, and that person I bought it off of (ebay) refered it as a 'test pipe'. I'm not running a cat and it blows people out with exhaust fumes behind me. Hahahaha. You're right though man, that Dynomax doesn't sound bad, not bad at all.

Mine sounds the best @ 2,500 - 4,000 rpm. I cannot get past 4,000 due to having a big cam and small fuel injectors and small mass air flow sensor. Not enough! When you do hit 4,000 rpm though, you're either burning out or moving like a bat out of hell. Getting ready to put the 19 pound injectors and 65mm MAF & TB soon. 58mm T.B./55mm 3.8L T-Bird MAF now. Hopefully will correct the problem, but it might just be my fuel curve since I am using an air adjuster for a 5.0L to conpensate for the calibration differences in my injectors and mass air..

Pete

[EVH5150]

Originally Posted by Psychopete

It's just a strait pipe that hooks on to my headers. I welded it right to my muffler. Basically just elminated it, and that person I bought it off of (ebay) refered it as a 'test pipe'. I'm not running a cat and it blows people out with exhaust fumes behind me. Hahahaha. You're right though man, that Dynomax doesn't sound bad, not bad at all.

Mine sounds the best @ 2,500 - 4,000 rpm. I cannot get past 4,000 due to having a big cam and small fuel injectors and small mass air flow sensor. Not enough! When you do hit 4,000 rpm though, you're either burning out or moving like a bat out of hell. Getting ready to put the 19 pound injectors and 65mm MAF & TB soon. 58mm T.B./55mm 3.8L T-Bird MAF now. Hopefully will correct the problem, but it might just be my fuel curve since I am using an air adjuster for a 5.0L to conpensate for the calibration differences in my injectors and mass air..

Pete

Sounds like a bad ass motor. Anyhow, I called a Local Ford dealership for a quote for a cat replacement and he found a direct fit aftermarket cat for about 350.00. How did you come up with all these modification ideas for your motor? I heard of a book called "Modifying the 2.8 and 2.9 V-6" But havent been able to find it. Heard it's got some interesting info.

[TheRangerOfDanger]

don't waste your money at the ford dealership - they will hike up the prices like nobodies biz. $350 is a rip off
All you need to do is find the measurements for the length of the cat and then for the diameter of the pipes coming in and going out. Then go search the web. Better yet, go to advance auto / auto zone/ your favorite auto parts place and tell them your truck info and they'll be able to get you a direct fit part for about HALF THE PRICE - literally!! this way you don't even need to crawl under and get measurements.

[EVH5150]

Thanks for the advice. I know i'm making a big deal out of nothing, I just want to make sure this warpig passes inspection so i aint gotta dick around with it a second time. that way I can get to fixing other things in the truck!!! Good truck, It's just a little anal, like it's owner. Thanks again.

[TheRangerOfDanger]

hey man, no worries. i don't blame you - your not making a big deal about it, you just don't want to have to do it twice, and that's understandable. I know exactly what you mean; it's fun to work on your truck, but it's alot more fun when you're doing things because you WANT to, not because you NEED to... been there before... most of us have.
It seems that each truck, just like it's owner, has it's own idiosynricies...

[Psychopete]

Originally Posted by EVH5150

Sounds like a bad ass motor. Anyhow, I called a Local Ford dealership for a quote for a cat replacement and he found a direct fit aftermarket cat for about 350.00. How did you come up with all these modification ideas for your motor? I heard of a book called "Modifying the 2.8 and 2.9 V-6" But havent been able to find it. Heard it's got some interesting info.

Yea, I got that book, and wasted 50 bucks on it. Doesn't have any details on modifing the 2.9L fuel injection system. At least my copy doesn't. Really, the only key to a performance engine is Mass Air Flow.

Most older Rangers have speed sensity, where the air / fuel mixture is calculated by using a table of defaults built in to the ECC. Unfortunately, there isn't much performance you can do with speed density, unless you spend some serious cash on ECC flashing, and horsing around.

In 1990 they came out with a MAF 2.9L in California only. They did this for emissions purposes. Some think MAF is bad, just because they have the thought "emissions = horse power killer". Most are, but MAF uses a meter to actually read how much air is coming into your engine, rather than making educated guesses.

This works by heating up very small coils, and the temperature drop caused by the air passing by send the voltage to the ECC indicating how much air flow we're dealing with. In my case I had to get an air adjuster which modifies this voltage being sent back on the fly. My engine will not run with out it. I used a 3.8L MAF which is calibrated different for a different ECC, so I gotta trinker with the air fuel ratio to make sure it's correct.

Just last night, I put on the 65mm MAF and 19 lbs. injectors. The tuning is way out of whack, but it's putting out a lot more torque than before. Doesn't sound like it has a turbo anymore . The hissing was very loud from my old MAF (too small). Hitting less RPMS, it seems like it's too rich, but I won't know until I pull the plugs to see what's going on.

Most modifications for all engines are the same. Just different parts. The bad part is, there isn't anything you can change with out having to change the other. If you build a performance motor, you gotta have all performance parts. Most upgrades, like upgrading injector size, will yeild no difference/if little at all with out a bigger cam and more air flow (T.B. / MAF).

Pete