throttle body spacer.

[Mr. Logger]

not sure but our cats have O2 sensors that adjust fuel mixtures and regulate how it runs. Because my Cats leak my O2's think my engine is running lean and it it has an abnormally rough idle. Question, How much would a complete exhaust cast with cats and Flowmaster 40 with 2.5in piping?

There are O2 sensors that adjust air/fuel ratio, and some that monitor the cat only. I doubt that your cats leaking is causing your O2 sensors to think you're running lean. This is because the cats are after the O2 sensors that control the air/fuel ratio.

would there be any way to re locate the o2 sensor, the oly reason im adimant on not having a catalytic converter is it makes my car sound like a vaccum.

Not sure why you would need to relocate the sensor if there is no cat...

 

[burtonbrd138]

There are O2 sensors that adjust air/fuel ratio, and some that monitor the cat only. I doubt that your cats leaking is causing your O2 sensors to think you're running lean. This is because the cats are after the O2 sensors that control the air/fuel ratio.

What is the cause of this lean code? The Cats leak BAD so what is it. I checked vacum lines

 

[Mr. Logger]

Anything that can affect fuel delivery. Pump, filter, injectors, pressure regulator. Could also be a vacuum leak somewhere other than the vacuum lines, such as any gaskets on the intake side.

 

[burtonbrd138]

ok so i am getting a P0174 Bank 2 Lean code so that, can be from a leak from the intake manifold gasket on whatever side Bank 2 is?

 

[Willard]

would there be any way to re locate the o2 sensor, the oly reason im adimant on not having a catalytic converter is it makes my car sound like a vaccum.

I would have different exhaust from the cat back before considering removing your cat.

Also, since you're a first generation, the O2 sensors have nothing to do with the cats. There is only one I believe on yours, and it's before the cat.

 

[Willard]

ok so i am getting a P0174 Bank 2 Lean code so that, can be from a leak from the intake manifold gasket on whatever side Bank 2 is?

Why don't you bring this conversation into another thread before you overtake this one...

 

[dylan_133]

I would have different exhaust from the cat back before considering removing your cat.

Also, since you're a first generation, the O2 sensors have nothing to do with the cats. There is only one I believe on yours, and it's before the cat.

so the first gen's can run fine without a cat?

 

[Willard]

Theoretically, as far as the computer knows, it doesn't exist anyways.

But, you probably won't gain anything performance wise if you remove it. In fact, you may lose a little. These motors in stock form and tune like back pressure, and without it your torque will suffer.

 

[RubySlow]

They use to sell TB Spacers as a heat spacer (Cools down the flow of air between the intake tube and the throttle body (Even though coolant passes around the TB) and gains massive horsepower!), anyways if your going to buy that, dont forget http://www.turbonator.com

 

[trucku]

If you want I can make a turbonator from a soda can of your choice.

 

[Blacksheep Josh]

Okay, there's a lot going on in this thread, but let me just get this together...

The first generation Explorers have no sensors in the catalytic converters, only before. I believe the 1991-1992 have one sensor, while the 1993-1994 have two sensors, one on each side. (Not positive about this prior part, but pretty sure from reading posts for a while).

Now, I believe some are asking can you run without a catalytic converter, the answer is yes. The catalytic converters help eliminate waste in the fumes, such as left over gasoline that didn't burn, they also provide SOME backpressure, which in turns gives the engine some performance, not sure how, but it does. If you take away the catalytic converter, you may lose a slight bit of performance, but I would think you can make up for this by running a slightly smaller pipe instead.

Or, as I'm planning on doing, and I haven't seen anyone else mention this, there are things called "high flow catalytic converters", they do the same job as a stock catalytic converter, except they allow exhaust to pass faster through them. I'm not sure about the performance areas of them though.

If I messed up anyway, please correct. I'm not an exhaust guru, I only wrote my opinion on the subject from what I've read/learned. If you're more educated in the area, feel free to post the correction. But I believe most of what I just wrote is true, or damned close.

 

[dylan_133]

i was thikin about running smaller pipe, prolly what ill end up doing. Those turbonator things are a joke. 55hp gain! i acually laughed when i saw that.

 

[aldive]

There is no need for a replacement cat, unless yours is bad. The stock cats flow just fine.

Further, there is no need for smaller pipe whatsoever.

 

[dylan_133]

alright well i know that you really know your stuff so ill take your word for it. man i cant wait to get my new exhuast though. thanks for all the advice, hopefuly i can return the favor in the future.

 

[seth247]

If you want I can make a turbonator from a soda can of your choice.

HAHAHAHAHAHAHAHAHHAHAHAHAHAHAH

i love it!


as for the exhaust, most people confuse backpressure for scavenging, where the inertia of exhaust gasses flowing out of the the exhaust manifold help to pull new exhaust out of the engine.

the ideal exhaust system will have no backpressure whatsoever, but will have excellent scavenging effects. backpressure does help scavenging but the backpressure is not the cause of the increased torque.

anyway if you want a spacer, get an intake manifold spacer. these have been proven to work.

 

[turbo cat]

1) backpressure is bad

2)exhaust velocity is good for torque (not going to big on the pipe size)and strait thru mufflers even see better #ers on the dyno then chambered due to the velocity staying up and not being disturbed by decompressing and baffles

3)removing the cat will not hurt performance however may cause you to fail an emmissions test and you will smell the exhaust a little more. my 4.0 only has a T3 turbo with a few feet of 3" pipe and it runs pretty well considering its not tuend and the 02 isnt hooked up

4) I would just leave the cat as you woulnt see much of an improvment in power and even the stockers flow ok if there not clogging up. if you want you can get an aftermarket converter like a carsound (magnaflow) cat

 

[Blacksheep Josh]

1) backpressure is bad

wait, what?

i've always thought, read, been taught that backpressure is needed... that to much backpressure is just as bad as no back pressure.

 

[turbo cat]

a smaller pipe will have higher backpressure which will hurt the higher rpms but help the lower rpm torque by creating a good velocity. a larger pipe will have less backpressure which is good for HP but kills low rpm velocity (kills torque) its all a balancing act

 

[seth247]

^^^^^thank you, that clarifys WHY "backpressure" helps torque.

I did not understand until now.


By the way turno cat, did you get my pm about the avatar?

 

[HahnsB2]

Backpressure is bad, period. Let me try to explain it...

The common misconception with larger pipe means less backpressure is wrong, too big of pipe lowers velocity and you get exhaust reversion which RAISES backpressure, too small of pipe also causes backpressure.