What smog/emission equipment do I delete???

1992MustangGT

15 Year Member
Sep 6, 2008
166
14
19
Washington State
I have a 1992 Mustang GT 5.0 which is all stock except for a cold air intake and larger throttle body and mass air meter. I want to remove all the emission/smog components from the engine to free up some horsepower. My question is can someone tell me each and every component I need to remove to accomplish this? Also tell me if there's any computer or electrical modifications I will have to make to run without the smog equipment, if any. I know I can remove the smog pump and the hoses connected to it, but that's the extent of my knowledge. What about the EGR valve, EGR vacuum solenoid, misc sensors, etc...??????? Also, since I'll be removing the smog pump, does anyone make an idler pulley to replace the smog pump? Or is there a website dedicated to explaining this process??? Eventually I want to install some shorty headers and an off-road H or X pipe (not sure which one would be better or produce more horsepower, H or X???) Your advise is appreciated.
 
  • Sponsors (?)


Smog pump will free up 1 hp at the most.

Well I just learned they some company has a EGR delete kit, H pipes sound better on mustangs. Also you can just get a shorter belt to bypass the smog pump once you take it off. As far as computer stuff I have no clue, I wouldn't image you would have to do much, or anything. BUT don't take my advice on the computer part.
 
There are no computer issues when deleting smog. Just make a block off plate for the spacer and plug the ports on the heads. There is no pulley needed, just run a shorter belt. X pipe has a raspier sound and hpipe has a deeper tone.
 
There are no computer issues when deleting smog. Just make a block off plate for the spacer and plug the ports on the heads. There is no pulley needed, just run a shorter belt. X pipe has a raspier sound and hpipe has a deeper tone.

Well I know there's more equipment than the smog pump to remove. What about the EGR Valve and EGR vacuum solenoid? These are both part of the emissions system. Can I remove them from the car? They also have electrical connectors plugged into them. If I unplug them, will it effect anything?

You mentioned making a block off plate for the "spacer" and also plug the ports on the heads (I'm assuming these are two different things???). What is this "spacer" your talking about and where is it located? And the ports on the back of the heads, I'm assuming this is where the cross over pipe bolts to??? So your talking about removing the crossover pipe and plugging the holes, correct?

Also, there's some sort of "box" that is mounted on the front frame rail next to the smog pump and the radiator. there are hoses and wires connected to this box. What is this box and what function does it have? Can I remove this box also?

Is there anything else to the smog/emission system besides the components I've mentioned?

And thanks for the advice on the X/H pipe. I'll go with the H-pipe for the deeper sound....Keep the advice comin guys. Thanks....
 
There's virtually no HP to gain. This isn't the 1970's here. The Mustang EFI smog setup is vitrually non-invasive. The most you'll gain is the 1/2HP the smog pump takes to spin. If you go with a cat-less H-pipe you can elim that, but other than that yanking off all the other stuff sometimes causes more trouble than it's worth.

Sometimes issues are caused by someone yanking off all that "HP-robbing" smog equipment. So they now have a surging idle and a CEL from yanking the EGR but they are making the most with that extra 1/2 HP.

besides, if the car is any sort of daily driver, then you want to keep your EGR. It isn't there for smog as it is for fuel economy.

That box on the front frame rail is the Carcoal canister which is used to vent fumes from the gas tank directly into the engine after passing it through activated charcoal. It robs 0 HP, and removing it may cause your car to smell like gas fumes which can potentially be dangerous.


But, if you still want to yank stuff off, give this site a read.

http://rjminjectiontech.com/?p=9

http://forums.mustangworks.com/f8/egr-elimination-48567/

Show yo the resistors and such you need to do to properly eliminate the EGR and TAB/TAD solenoids to keep the engine functioning as it should.

But i would think hard about removing the EGR. Nothing to gain by removing it. It's shut off at idle and WOT and only fucntions at part throttle cruise
 
^ exactly

only real reason to remove it is for cleaning up the bay, or not reinstalling it on a new motor.
If mind hadn't already been bypassed I wouldn't waste my time. There are many other ways to free up hp on a stock motor
 
tannerc91gt;8131961 There are many other ways to free up hp on a stock motor[/QUOTE said:
Bingo


I mean to properly delete the EGR you would have to pull the lower intake off and block the EGR ports at the heads. Then you'd need to purchase the necessary resistor pack to turn off the CEL.

So you are out $15 for the gasket kit, $15 for the resisitor pack, a couple hours of labor and you've gained nothing at all...if anything it will cost you money in the long run due to the lowering in fuel economy.


With the smog pump, if you ditch the cats and NEVER plan on putting cats back on, then yank it away. You'll still need resistors to clear the codes for the TAB/TAD solenoids. Basically upon cold startup, the smog pump provides O2 to the exhaust ports which then travels to the 1st pair of cats in order to accelerate the conversion of byproducts of combustion. The 1st pair of cats are close to the engine so they warm up and function first. Once the car warms up, the main cats provide the main converting function. In that case, the computer, via vacuum, will divert air to the tube that feeds o2 to the main cats to aid in conversion there. So basically the smog pump and tubing just feeds o2 to the different cats either viat the long tube or through the heads.

If you ditch the cats, you can eliminate all this and then trick the solenoids on the backside of the pass fender with resistors. 1/2 HP gain here.

The charcoal canister draws fuel vapor from the tank through the activated carbon where it is drawn into the engine and consumed. Nothing to gain here by removing this other than looks...and it's not really that noticable. To properly remove it, you need to install a vented gas cap and then trim te line running from the tank and position it so the explosive gas vapor can discharge in a well ventilated area.
 
Well it sounds like removing all this stuff isn't going to gain me anything and could possibly cause me problems. Guess I'll scrap this idea. The reason I was considering this is because on older cars, such as my classic cougars and my 79 Bronco when the smog stuff was in it's infancy, you could gain driveablity and possibly a little hp and gas mileage by removing all this junk. But that just goes to show how far Ford has come in making this stuff function without effecting driveability and the such. Thanks for the advice guys. You've saved me alot of headaches.
 
  • Like
Reactions: 1 users
With the smog pump, if you ditch the cats and NEVER plan on putting cats back on, then yank it away. You'll still need resistors to clear the codes for the TAB/TAD solenoids. Basically upon cold startup, the smog pump provides O2 to the exhaust ports which then travels to the 1st pair of cats in order to accelerate the conversion of byproducts of combustion. The 1st pair of cats are close to the engine so they warm up and function first. Once the car warms up, the main cats provide the main converting function. In that case, the computer, via vacuum, will divert air to the tube that feeds o2 to the main cats to aid in conversion there. So basically the smog pump and tubing just feeds o2 to the different cats either viat the long tube or through the heads.

If you ditch the cats, you can eliminate all this and then trick the solenoids on the backside of the pass fender with resistors. 1/2 HP gain here.

I have some more questions for y'all....I do plan on yanking the cats and installing an off-road h-pipe setup, therefore, like you said, I could remove the smop pump. But if I leave the smog pump on the car after removing the cats, will it effect or hurt anything? The reason I ask is because you mentioned if I remove it then I will need to "trick" the TAB & TAD solenoids.

Which leads to another question...What is the function of the TAB/TAD solenoids? What are they used for? Do the TAB/TAD solenoids have anything to do with the CATS?
 
I have some more questions for y'all....I do plan on yanking the cats and installing an off-road h-pipe setup, therefore, like you said, I could remove the smop pump. But if I leave the smog pump on the car after removing the cats, will it effect or hurt anything? The reason I ask is because you mentioned if I remove it then I will need to "trick" the TAB & TAD solenoids.

Which leads to another question...What is the function of the TAB/TAD solenoids? What are they used for? Do the TAB/TAD solenoids have anything to do with the CATS?


They stand for "Thermactor Air Bypass" and "Thermactor air diverter". Basically they control vacuum to the two valve located downstream of the smog pump that either divert air to the heads, or down into the H-pipe.

You can leave the smog pump on and all hooked up. Most if not all h-pipes come with the hook-up for the smog tube into the h-pipe. Just hook it up like normal.
 
i have a 68 stang with a efi swap and t5 swap for over 2 years. i have no egr stuff at all, and it is a clean engine bay and hauls ass. the only thing is it always has codes for emissions but i have no light to annoy me.i just check codes every once in a wile. i use a A9P ecm also not the A9L
 
I would keep the egr like some of these guys mentioned. Only reason i'm deleting mine is because i'm switching to an edelbrock victor 5.0 manifold which does not have egr provisions or pcv either.
 
FYI you can delete the TAD/TAB noids and the code does not have any adverse effect in the fuction of the car running. I ran this way for a while when i didn't have a smog pump. I just put my pump back on to run a catted pipe.

But for the EGR, when i had a code 33 stored, it did affect the way my car ran. Some guys claim the EGR creates idle probs, some don't.
 
I would keep the egr like some of these guys mentioned. Only reason i'm deleting mine is because i'm switching to an edelbrock victor 5.0 manifold which does not have egr provisions or pcv either.

Sounds like the EGR is fairly important to keep on the car, which leads me to this question about aftermarket intakes. I eventually plan on swapping out my stock manifolds for a Trick Flow setup. My question is...and this may be a dumb quesion, but oh well: do aftermarket manifolds have ports to mount the EGR or is it just the Edelbrock manifold you're using that doesn't have it?