time to do some quickie exhaust work.

 

front catalytic converter seems fine. from the second catalytic converter(or resonator?) back it all needs to go.

 

the second converter has a hose running into it and a sensor plug .

 

can i do away with second converter and just run straight pipe?

what about the rubber hose and sensor?

thanks

 

 

----------------------------------------

ok, got back under the car today and i can reuse the back conveter. just need to punch screen out of it.

 

how necessary is that oxygen sensor in it?

and that rubber hose?

 

never did much exhaust and i'm working on 2 different cars at the same time. HELP!!!

follow the rubber hose up to the back of the motor and unplug them, cap off teh ports the hoses connect to with a piece of rubber inner tube and a hose clamp

 

you can eliminate the whole mess if you can find a plug for the exhaust port. the rest of it just bolts to a bracket on the back of the head.

 

you can make a block-off plate or just weld some random bolt to the end of the chopped tubing

 

but yes, it can be eliminated and later models exhasts will fit the same. ask for a 94 loyale unless they are making one from scratch.

 

if that's the case have a 2 inch cherry bomb in place of the resonator and do away with the muffler, turn the timing up to 10 or 12 deg

Hi Bill,

would you care to enlighten us as to the

car

year

fuel system

state it was manuf. for

 

this little help to us may in turn

help us help you

as you asked us for help

this is my 86 carbed. not sure the state of manufacture.

 

my other project is my crown vic which i'm changing to duals.( There is an excellent forum if anyone here has a crown vic or grand marquis. just pm me if you need details)

 

a flange gasket and long screwdriver and i can reuse my back converter and leave hose and oxy. sensor in place.

 

im pretty sure the oxy. sensor is bad(from info in old threads)

should i just replace with the cheapest generic?

thanks again all.

from this info

and the fact the car is NOT 4wd

it can be gleaned

 

this car has an ECU and a feedback carb.

 

If you eliminate the 02 you would also have

to make some changes to the carb as the ECU

would have no A/F reference voltage.

 

A generic < 20 $ Bosch 02 sensor can be used.

 

I am sorry I know not about the "rubber" hose

to a cat?? Seems pretty hot for a rubber tube.

 

We need GD or Gloyale to spell this one out.

 

It could be the air injection tube

to provide 02 to the cat to complete

the unburned hydrocarbon combustion.

 

A newer cat could be fitted

eliminating this necessity.

pics would definately help yall help me. (a compatable memory card reader is in the budget)

as i've mentioned about my car before, it has underwent some real backyard mystery modifications before i got it and the exhaust is no exception.

the second converter has maybe a foot of pipe on the back of it and just sits in a bigger pipe that makes up the rest of the exhaust. no clamp or anything.

Dont see how any exhaust ever made it all the way to the end of the tailpipe.

sorry Bill I do not mean to be rude but

some of us folks don't get a chance to read

every other post, posted by posters.

 

Or remember for that matter as some of us have

"senior monents" (speaking for myself here).

 

Thus the more info one can give

at the time of posting a "new" or different problem

helps us help you..

i know a lot of people come through, but with the personalized help i get it feels like yall do actually know my car. appreciate you all.

 

oxy sensor part #11027 the one?

thanks again

The rubber hose feeds the Air Suction Valve. If you're replacing the CAT, it can be removed. Just trace it up to it's origins in the engine bay. Cut and plug it. The ports on the heads will still supply the ASV. The whole ASV system can be eliminated actually, but the easiest thing to do for now would be cap it. Or actually just leave it if you're not replacing the cat and it's not leaking or broken.

 

There should not be an Oxygen sensor in the second cat. The only O2 sensor should be in the front cat, between the arm of the *Y* piece.

 

The dual jacket pipe is just for noise reduction and corrosion protection. The bigger pipe is just sleeved over the inner.

 

to run you're new pipe, use a size just slighlty bigger than the inner pipe. Sleeve it between the 2 layers, over the inner, but inside the outer. Then clamp and/ or weld. Works well, I did this on an 86 Carbed 2wd sedan.

To my knowledge Subaru never used that style cat with the air injection tube running into the side of it. That was mostly used on cars equipped with smog pumps.

 

Subaru's system was to inject air into ports built into the heads right above the exhaust flange (on EA82's).

 

I would say you have someone's attempt at plumbing in an aftermarket 2nd cat to pass some inspection when they found it expensive and difficult to replace the built-in cat contained in the y-pipe. Their solution (a valid one) was to add a second "universal" cat. They just used one that had the AIS port and figured a way to hook it in I suppose.

 

Sounds ghetto - I would yank it out if it were me. Chances are good that if it wasn't done right it could cause more problems than it's worth.

 

GD

you are correct Gloyale. i was under there today again and the back has just the hose.

i had everything loose from the manifold back and the oxy sensor is in the front converter. Just blended together in my tired mind.

 

running it unhooked right now right before second converter. is loud as hell, but also seems to have less power this way.

Maybe not enough backpressure?

running it unhooked right now right before second converter. is loud as hell, but also seems to have less power this way.

Maybe not enough backpressure?

 

Maybe. But most of your scavenging comes from the headers (y-pipe) itself. It's usually not a problem to go with larger pipe or no pipe after the first cat. At least it's never really affected any of the one's I've run that way.

 

Perhaps your y-pipe is leaky. Do you get backfireing at times? That's indicative of a working AIS and a leaky y-pipe. Too much fresh oxygen combines with unburnt fuel and often ignites in the muffler.

 

GD

and you are correct also GD . this car has a lot of ghetto fixes. could have spent a couple years in mexico!