Is there anyplace on line to look at ford parts diagrams? like the microfische they use at the dealerships.

Does anyone know if I can put dual cat. converters and dual mufflers for a true dual exhaust on my 88 Bronco with a 351W? I know it has an air outlet pipe on my stock cat. conv. What does it do or connect to?

Can I put two cat's. on it and tee them together to hook back to the factory line?

 

a single exhaust will perform better the duals. plus what your asking isnt a true dual setup anyway. I recommend going with a bassini Y pipe with hiflow cat (1) into your choice of muffler then 3"s out to stock location.

 

Ditto, to Kem's idea. Search this forum and you will find that a number of us have gone to the Bassani setup. True duals are just a PITA to find room for under the Bronco anyway. To keep from confusing the EEC computer, you must make certain the O2 sensor is getting the combined reading from BOTH banks of cylinders and this is not possible unless you run a cross-pipe with the O2 sensor in the cross-pipe in a true dual setup. Again, finding a decent route and space under the truck to do this is anything but simple.

The "air outlet pipe" you referred to is the exact opposite. Its an air injection input port from the smog pump that must be fed to make the cat properly heat so it burns off the additional crud that the combustion cycle doesn't get. There is also a check valve and diverter valve that controls this airflow. The check valve can be seen from under the truck but the diverter valve is nearly hidden behind the engine against the firewall.

I know I will sound like a bad CD when I say this because I've said it so many times before. When running exhaust on a Bronco DO be certain to exit the pipe in (or very near) the stock location. This is a safety/carbon monoxide issue. Out the rear is a potentially lethal situation.

 

OK, Thanks. If I replace my stock exhaust manifolds with tublar units, will it cause overheating in traffic, especially in the summer? Will it ad a lot of noise inside? Keeping in mind that with trans and gearing I have it turns about 3000rpm on the highway.

 

if you get ceramic coated headers your under hood temp will be less then it is with the stock manifolds.

 

Guys, what size pipe should I run on the single exhaust? 2 1/2" or 3". If I run 3" from the wye through the cat and out through a single would I be able to tell any power gain over the same cat and muffler only using a 2 1/2" pipe? There is a big difference in cost for 3" over 2 1/2". Consider that I have an 88 Bronco with 156k miles on it. I would like to make it run better with a little more power, but I am not going to race it or do any heavy pulling.

My Bronco is currently completly stock. I am considering installing the following items:
Mallory HyFire VI-A Digital CD Ignition
MSD Distributor Cap and Rotor
8.8mm Silicone Plug Wires
New Spark Plug (brand ?)
Throttle Body Spacer (Motorvation or Airaid Power Aid or Powerdyne Power Plate ?)
K&N Filter(maybe a cold air kit or fabricate my own box)

Any reccomended order or other items I should consider?

These are in adition to a Catco Perf Cat Converter and (Flow Maste or Dynomax Muffler ?)

 

i say stick with 2.5. you could go 3" if you ever plan on a 5.8 swap but otherwise keep it 2.5 also ask them to route it up as high as possible to the frame this will keep it out of harms way. my shop didnt do that and my tailpipe sits well below the body which isnt good

 

Let make sure I understand. I already have a 5.8, so still stick with the 2.5" or should I use the 3" since I already have the 5.8?

 

oh sorry bout that, yes go to 3" all the way out. get a hiflow cat and muff of choice. if you get a flowmaster have them put it in at a slight angle like this \ it will help not to resonate in the cab so much.