Bronco Forum - Full Size Ford Bronco Forum banner
1 - 20 of 36 Posts

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #1 ·
ok guys im not in anyway askin or lookin for a fix for this system, ive been readin through and searchin many threads about this and have only one question.......i want to just say F the air injection and get rid of the headace, the cats are comin off when i get the new exhuast anyway, im planning on removing the line to cat, diverter valve, crossover pipe, line to pump, the two vacuum soleniods, and the smog pump breather, ill cap the holes in the back of the heads and cap the line to cat nipple on the exhuast, since the EGR runs from the lower intake to the upper before the TB ill leave that system put

my question is since im only getting rid of the fresh air injetion system on the exhuast side would i suffer on MPGs or performance?

im not in anyway trying to gain HP or TQ, im just not f*ing with the line to cat anymore, so when i remove the old rotted out exhuast i wont have to deal with anything other then putting the hedders, Y pipe, 40 series and tail pipe on, i will be getting the sixltre ignition within the next month or so too

so will i suffer or will the new exhuast and sixltre upgrade make up for the loss, it will be a DD once im finished with everything but no long comutes, work is just within 20 miles from home, i do some weekend wheelin at a mud hole thats at the end of my street
 

·
Registered
Joined
·
258 Posts
I doubt you would notice a change. I don't know for the emission testing if you would pass (not knowing if you would have to or not).
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #3 ·
theres no emissions law here(south florida) except the must have cat law but who gonna know......are you sayin it wont affect anything? and if i prefer to remove it i can without a change?
 

·
Registered
Joined
·
11,117 Posts
I lost mileage without a cat, and a little bit of low end torque.

And yeah, they will know, all it takes is a cop with one of those extendable mirrors (and yes, they have them) to take a quick peek underneath.

If you get a cat that doesn't need the extra air, then you can still get rid of all that stuff and be fine... but if the stuff is working, just leave it on.
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #5 ·
thanks guys, its not workin all to well, so if i just throw a high flow catco in there i should be able to remove it all and be just fine right?
 

·
Satyr of the Midwest
Joined
·
17,747 Posts
It'll feel weird at part-throttle, especially around town, and you will lose mileage. Not at first, but once the PCM 'corrects' the long-term trim, you will.

but if the stuff is working, just leave it on.
Absolutely. No reason to screw with a system that will have absolutely no effect on perceivable performance (the air injection). It just invites more problems, and can render the oxidation bed useless (the second part in a TWC). HEGO and reduction bed light-off can also take much longer without it.

What's wrong with the system right now?
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #7 ·
well the pump is about seized, the crossover pipe keeps plugging up with what looks like gunky carbon buildup, and the line to cat pipe rotted off the Y-pipe, so i figured if i can remove the system without any probs, i could put a york or my old a/c compressor on there for OBA, i know its just a DD right now with some weekend muddin but i plan on makin it my trail rig once i buy a little car for DD use, so i figured since the system isnt realy doin much right now anyway id just go ahead and replace it with OBA
 

·
Satyr of the Midwest
Joined
·
17,747 Posts
Pumps aren't expensive, even boneyard ones can be resurrected, and can easily be lubed if you take off its rear plate. The crossover pipe keeps plugging because you probably have a bad check valve in it. An exhaust shop can make and attach that line going to the Y-pipe for very little cost. It's just a piece of 3/4-inch steel tubing crimped on at the cat end. You can make one out of copper plumbing pipe and high-temp hose if you really want to. That or Sixlitre may chime in with that handy-dandy kit offered exactly for this purpose.

:toothless
 

·
Registered
Joined
·
11,117 Posts
:stupid

Even the replacement ones from the parts stores are cheap.

Good high temp silicone hose is pretty reasonable too.
 

·
Registered
Joined
·
258 Posts
Now if you remove the cats you will might see a difference +/- a little. If you remove the smog pump you will gain a little on HPs due to less drag on the engine but your going to need a smaller belt.
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #12 ·
Now if you remove the cats you will might see a difference +/- a little. If you remove the smog pump you will gain a little on HPs due to less drag on the engine but your going to need a smaller belt.
well i wont need a smaller belt, b/c ill be putting OBA in place of the smog pump, im just gonna take it all off, and run just a high flow cat, i dont have emissions testing here and i DONT want to fix it again, i just wanted to know what i would lose if i took it off, the EGR system will still be in place since it isnt connected to the air injection system, i also gotta do some more research on the gt40p heads since i am considering it as long as i can keep the EFI, and i hear you cant use the air injection with the gt40 heads so ill be removing it anyway
 

·
Registered
Joined
·
11,117 Posts
If you remove the smog pump you will gain a little on HPs due to less drag on the engine but your going to need a smaller belt.
You have no idea what you're talking about.

Drag from the AIR pump is measured in tenths of a horsepower.

im just gonna take it all off, and run just a high flow cat, i dont have emissions testing here and i DONT want to fix it again
Again, it's suggested that you don't remove the system... just needs a little care considering it's 12+ years old... but if you do, make sure the catalytic converter you buy doesn't need it.
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #14 ·
ya i dont know what im doing know i just did ALOT of searching on the gt40p heads and as i see it the horsepower and torque gains arent worth the headache of modifying everything to get them to work......so i might just see about taking the whole system off and rebuilding it or replacing it with new parts from ford, but i still dont think its worth the money to restore the system if itll be fine without it.....thanks for the help guys but i dont have enough info to make a decision yet
 

·
Practicing Infidel
Joined
·
15,299 Posts
The number one thing you MUST retain is threaded holes

(in the right place) for your O2 sensor/s. Without those you'll be suckin' gas and performance will circle the bowl too.

You do realize that some kind of replacement Y-pipe needs to be made or bought, as your stock Y-pipe "IS" your first cat.

That is to say your two headpipes off the manifolds go straight into the first cat. After that is takes a terribly restrictive "S" bend up over one of your crossmembers and heads straight into the second cat.

If it weren't for the hellishly kinked and restrictive passenger's side headpipe, I'd say that "S" bend between the cat's was you're biggest restriction.

What I'm asking is "what" are you replacing the Y-pipe with ? if you're going to tear off your cats ? They are "one and the same".

With hollow cats or not, the stock Y-pipe "IS" the restriction and it's costing you 3 mpg easy. Do the ignition upgrades right now, so you can be saving mpg and $$$$ while you save up for the Y-pipe.

Frankly I got my best mileage with the 3" ($55.00) Catco catalytic in place (replacing the stock cats). I hit 21.6 mpg on my best day.....interested ?

Sixlitre
 

·
Registered
Joined
·
258 Posts
You have no idea what you're talking about.

Drag from the AIR pump is measured in tenths of a horsepower.
Obviously, I have some idea of what I'm talking about since you even stated there would be a gain in HPs, thank you!!!!!! I didn't say he was going to get a lot. Granted he's not doing a underdrive pulley system which would net him up to 25 HPs (depends on how small he goes on the crank pulley).

Back on Topic:

Now to answer the original question it does not appear it would make a noticeable change as I originally stated.
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #17 ·
The number one thing you MUST retain is threaded holes

(in the right place) for your O2 sensor/s. Without those you'll be suckin' gas and performance will circle the bowl too.

You do realize that some kind of replacement Y-pipe needs to be made or bought, as your stock Y-pipe "IS" your first cat.

That is to say your two headpipes off the manifolds go straight into the first cat. After that is takes a terribly restrictive "S" bend up over one of your crossmembers and heads straight into the second cat.

If it weren't for the hellishly kinked and restrictive passenger's side headpipe, I'd say that "S" bend between the cat's was you're biggest restriction.

What I'm asking is "what" are you replacing the Y-pipe with ? if you're going to tear off your cats ? They are "one and the same".

With hollow cats or not, the stock Y-pipe "IS" the restriction and it's costing you 3 mpg easy. Do the ignition upgrades right now, so you can be saving mpg and $$$$ while you save up for the Y-pipe.

Frankly I got my best mileage with the 3" ($55.00) Catco catalytic in place (replacing the stock cats). I hit 21.6 mpg on my best day.....interested ?

Sixlitre
im gonna put the bassani y-pipe with or with out a high flow cat on, im gonna retain the O2 sensor and cap the injection nipple, i just wanna know if i remove just the air injection will i suffer performance or MPGs....im leavin the EGR and all that on there since the only thing the air injection ties into is the exhuast and the heads which can all be capped but will i suffer.....im doin the sixlitre upgrade soon after the exhuast too
 

·
my bko ate my money
Joined
·
2,326 Posts
Discussion Starter · #18 ·
Obviously, I have some idea of what I'm talking about since you even stated there would be a gain in HPs, thank you!!!!!! I didn't say he was going to get a lot. Granted he's not doing a underdrive pulley system which would net him up to 25 HPs (depends on how small he goes on the crank pulley).

Back on Topic:

Now to answer the original question it does not appear it would make a noticeable change as I originally stated.
thank you my main prob in deciding right now is im getting all these messages and replys sayin im gonna suffer alot pluss sig claims it will mess with the puter too, i dont see how removal of the system would adversly affect everything else
 

·
Practicing Infidel
Joined
·
15,299 Posts
thank you my main prob in deciding right now is im getting all these messages and replys sayin im gonna suffer alot pluss sig claims it will mess with the puter too, i dont see how removal of the system would adversly affect everything else
Sig's got some valid experience here

I'm a little concerned that your pipe between the heads keeps gunking up. Have you got serious blowby ?

I was forced into re-installing my air pump (for two years) when Austario went to emission testing a couple of years back.

It didn't hurt my mileage or performance and it was alot cheaper and easier than I thought to restore.

$60.00 got me a Cardone rebuilt air pump, I scored the pipe for the back of the heads and all the hoses from a yard for $10.00 and this kit and some soldering;

got it all working fine again.

All that said I pitched my pump as soon as my Bronco became age exempt (forever:chili:) a few years back.

I've got reasons because my V-belt set up makes plug access pure hell, but your 92' has no such problem, so why jeopardize your daily driver's mileage ?

Sixlitre

p.s./
Good call on the Bassani, but why wait even one fill up longer to do the ignition upgrade ?
 

·
Satyr of the Midwest
Joined
·
17,747 Posts
I still say his check valve in the crossover pipe is bad. That's the ONLY way carbon can get up there.
 
1 - 20 of 36 Posts
Top