Bronco Forum - Full Size Ford Bronco Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
959 Posts
Discussion Starter #1
I am sick and tired of the exhaust smell from my 79 bronco. I have headers and duels with magnaflows. If I put some kind of high flow cats on it would that keep the exhaust
 

·
Premium Member
Joined
·
1,520 Posts
This plus making sure your carb is tuned correctly. I have a stock exhaust set up with cat and FITech fuel injection and I get no exhaust smells in or around the Bronco. Just like a modern vehicle.


Sent from my iPhone using Tapatalk Pro
 

·
Ford Hoarder
78 & 92
Joined
·
6,994 Posts
I agree with the above that it will help. I have added one to a truck I use mostly hooking up trailers and such for the same reason.
I used a OBD-1 Metal Substrate Vibrant Converter on mine. https://www.summitracing.com/parts/vpe-7102 You can actually hold these up to light and see threw them. As an added bonus on the truck I installed them on they also deepened the exhaust note and took away some drone, much like a resonator.

Be Aware that just because the smell is not there does not mean that the potentially dangerous part of the fumes is not.
 
  • Like
Reactions: trustyrusty

·
Registered
Joined
·
959 Posts
Discussion Starter #4
I have tuned until I am blue in the face. Where should I put the converters as far as close to the front or toward the rear. I have had this bronco for over 17 years and am thinking about just selling and getting a newer truck. It is my daily driver
 

·
Registered
Joined
·
3,428 Posts
do you have duals out both side?
I always had fumes inside when I had my duals out both sides
I made true duals with both out right side in factory location and eliminated that part

do you notice more when stopped at idle?,with heater blower running?
on both my trucks,my rusty piece of crap and new to me 79 I would get fumes at idle,but they were from heater ,either sucking into air inlet from bad hood to cowl seal, rusted air box floor on old truck, and most likely culprit engine blowby and pcv sustem not functioning as intended
my current 79 I rerouted a poorly set up pcv and made sure I had fresh air into pcv system hooked up to air cleaner like factory did
that took care of my noxious fumes at idle with heater on
an oil leak burning off engine will also get sucked into heater inlet air and make it stinky and any not sealed up holes in firewall will allow air to come into cabin as cooling fan forces all air into firewall across engine
next time you stop and idle ,shut off blower motor see if it helps
I did that for a couple years on my rusted out truck ,
I plan on running a pair of cats on my project truck to clean up the exhaust
 

·
Registered
Joined
·
959 Posts
Discussion Starter #8
I had the exhaust out the back and think that was most of my problem. Yesterday I turned them out behind the rear tires. I have a vintage heat and air with no outside air getting used. I think some of my problem is the engine is about ready for a rebuild. It has blow by and my tailpipes are black on the inside. I have tried to lean up the carb but it is always too lean going down one jet size.The strong exhaust smell has just started in the last year
 

·
Addicted to Junk
85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
Joined
·
13,008 Posts
I installed a magnaflow spun mettalicat on my 85 precisely to cut down on fumes.

Here's a pic through the cat



You want it as close to the engine as possible. Mine is right after both headers merge

 

·
Registered
Joined
·
959 Posts
Discussion Starter #10
Which high flow cats should I buy for my 79 bronco. I want the fumes to be less. Also will the high flow cats help with drone of 40 flowmasters. My exhaust goes out behind the rear tires.
 

·
Registered
Joined
·
959 Posts
Discussion Starter #11
Also how long will a high flow cat last. I read somewhere they only last 36000 miles. IS this right?
 

·
Ford Hoarder
78 & 92
Joined
·
6,994 Posts
The cats will help clena up the exhuast, which usually means less fumes on these rigs. They are very prone to getting fumes into the rear window expecially.

I am not sure how you can just say a Cat will last XXXX miles, there are several variables that will come into play. How well the engine is tuned, how much oil does it put out, what kind of fuels does it see, etc...
From my own experince the high flow cats will help dampen the sound a little, very similair to a small resonator. It maybe just enough, but I would look into a 2nd muffler or replacing what you have as well.
 

·
Registered
Joined
·
959 Posts
Discussion Starter #14
The engine is new. I run 93 octane gas it is tuned correctly I want to make the exhaust fumes less if I can.
 

·
Registered
Joined
·
1,066 Posts
Just added one to my 1995 5.0. Headers do a much better job of scavenging exhaust - so without a cat, you will get some exhaust fumes. This isn't just the Bronco - although it will definitely seem worse with the top off on a Bronco with stock configuration or even side exist exhaust.

"High flow" cats are pretty a much a misnomer nowadays. I've witnessed dyno numbers for several different V8 powered vehicles (modern and older) with and without cats installed. I guarantee you, without a dyno, the person driving would not be able to tell the difference.

No need to spend a ton of money - Flowmaster makes some universal cat converters that cost well under $100.
 

·
Registered
Joined
·
959 Posts
Discussion Starter #16
I just want them to last longer than a few miles hate to spend money then 40000 miles they are junk
 

·
Registered
Joined
·
1,066 Posts
I just want them to last longer than a few miles hate to spend money then 40000 miles they are junk
Unless you're running pig rich, any decent universal cat should last more than 40K miles.
 
1 - 19 of 19 Posts
Top