smog pump removal?

**firsttime5.0** · 07-21-2009, 03:23 PM

ok so was looking at another thread and seen something about a smog pump removal. i am wondering what the benefit is of removing it and if i plan on removing my cats do i need to do this? also how do i keep codes from jumping up when i remove my cats?

**Tony71502** · 07-21-2009, 03:36 PM

Cats are independent of the smog system as far as I know, at least they are on fox bodies.

For fox bodies there are eliminators to plug into the egr harness to get rid of the CEL.

Basically removing it will:
-Lose 15 lbs (on a fox body, maybe not sn95)
-Increase combustion chamber temperatures and also provide more oxygen to the combustion chamber when NOT at wide open throttle(the egr is closed at WOT). This increase in CC temps also increases NOx emissions
-Free up some working space in the engine bay

**White5.0** · 07-21-2009, 03:37 PM

you will benefit because taking it off will free up a few horsepower since there wont be as much load on the engine. and you will also remove some weight.

all it does is pump air into the cats to help burn fuel to make your emissions better

**firsttime5.0** · 07-21-2009, 03:50 PM

hmm i see ... thanks guys! what all is needed to remove said smog pump? is it a job that can be done by your average joe or is there to much involved? see as i said i wanted to eliminate the cats and i would also like to eliminate the a/c stuff seeing how it either needs charged or needs a pump and i dont really use it anyway.. anyone ever done this either?

**White5.0** · 07-21-2009, 04:03 PM

if you are just removing the smog pump, i think you can just unbolt it and buy a shorter belt. if you are removing the A/C as well, you will need to buy a bracket that either relocates the belt tensioner or moves the power steering pump up where the A/C used to be. TrickFlow, Ford Racing, and March all make brackets for deleting the A/C.

here is my car with the TrickFlow A/C delete, which relocates the belt tensioner. my smog pump is also removed:

**Tony71502** · 07-21-2009, 04:16 PM

I don't know about on a sn95... but on a fox body the egr injects inert exhaust gas into the intake to dilute the A/F ratio, which in turn reduces combustion chamber temps and improves gas mileage. The tube between the cats is not for injecting oxygen, but rather for routing some exhaust gas to the intake system (at the egr spacer).

**firsttime5.0** · 07-21-2009, 04:21 PM

wouldnt that also heat up the a/f mixture cutting down hp? i mean cold air intakes improve hp by allowing more flow of colder air so by throwing exhaust gas would heat it up? also cant the ac pump be left in place to act as an idler pulley or does that defeat teh purpose of getting rid of it?

**White5.0** · 07-21-2009, 04:27 PM

Originally Posted by firsttime5.0

also cant the ac pump be left in place to act as an idler pulley or does that defeat teh purpose of getting rid of it?

kinda defeats the purpose. leaving it there does 2 things that you dont want : 1)leaves weight there that could be removed and 2) still leaves a slight drag on the engine that wouldnt be there if the A/C was completely removed

**Tony71502** · 07-21-2009, 04:40 PM

The exhaust gas being pumped into the combustion chamber is a much lower temperature than the combustion process. Heat is transferred to the engine block and internal components rather than being completely transferred to the exhaust gas. There is also heat loss in the headers and midpipe. When injected into the combustion chamber, due to being colder than the combustion process, it actually gets heated up and in doing so acts as a heat sink. The smog system is not active at wide open throttle and therefore does not rob horsepower at full throttle. The pulley may steal 1 hp from you from parasitic drag.

During normal driving conditions (Not wide open throttle) there is exhaust being pumped into the engine which reduces your emissions and improves gas mileage. You will lose some gas mileage by deleting the smog system, you will also have higher oxygen content and combustion chamber temperature(which is good until you have detonation) and will improve performance during normal driving(again not during WOT).

**firsttime5.0** · 07-21-2009, 07:00 PM

so is this all something that can be done by a weekend mechanic or should it be entrusted to the pros?

**frankstang** · 07-21-2009, 07:14 PM

Originally Posted by firsttime5.0

so is this all something that can be done by a weekend mechanic or should it be entrusted to the pros?

It's a very simple job.
You'll have to either cap the tubes going to the back of the heads or remove the tubes and buy a couple plugs for the hole in the rear of the heads. Either way will work.

I ended up removing mine because the air pump self destructed internally. (common), and the pulley would no longer turn.

**scott5** · 07-21-2009, 07:48 PM

I didnt really read into thsi much, but the few posts i did read you guys are talking about foxbodies when the sn95 is different. You must have a ac delete pulley on the sn95 if taking off the ac and the smog you can just take it off and no pulley needed just a smaller belt.
As far as the egr the main problem is that you have a tube going from your manifold up to your valve which you can get away with just capping off or buy a set of LTs with the egr already deleted.
I removed the ac and smog from the first car and my second car there is no way i was taking off ac and never will again and the smog was already removed with MAC lt headers with the egr delete

**fork5o** · 07-21-2009, 08:21 PM

its really not very hard to do. like was said, you have to cap the hole in the intake, i kept a little bit of the rubber tube that connects the two tubes to the back of the heads and plugged it, cap off the exhaust manifold, and also the mid-pipe. as for the egr sensor, just put a plate across it to hold the sensor down so it doesnt throw a code. and a smaller belt of course.