Question for gearheads

[bagrat]

Ok ,first off I know little to nothing about cars...don't hit me

I have this sticking out of the front of my engine, I believe it is the manifold and catalytic converter combined. I think this is true because, websites are labeling it as so (catalytic converter replacement) and I think I've spotted the air an o2 sensors going into the top and bottom of it...maybe not. Is there a catalytic converter somewhere in that thing?


A friend is telling me that it is just a stock header only and that the converter is located near the rear before the exhaust. described as a wider diameter metal tube. I did see this but did not find what looked to be sensors running to it. what is this?

but he is also telling me this is another stock header and it is labeled on it's website as a "Headers w/ High-Flow Catalytic Converter"


^so is that wider portion on the bottom the cat or no? (more importantly the top picture)? is it what the website says it is?

 

[Dago]

It's an alien anal probe, they are just waiting to catch you in an unguarded moment.  That's where they always store them.  Beware.

[Devil 505]

Yes that is the catalytic converter and O2 sensors. ANY passenger vehicle built in 1996 and after will have sensors before and after the converter. The actual placement of the equipment on the vehicle will vary, but the converter will ALWAYS be between the O2 sensors.

[CAP1]

Ok ,first off I know little to nothing about cars...don't hit me

I have this sticking out of the front of my engine, I believe it is the manifold and catalytic converter combined. I think this is true because, websites are labeling it as so (catalytic converter replacement) and I think I've spotted the air an o2 sensors going into the top and bottom of it...maybe not. Is there a catalytic converter somewhere in that thing?
(Image removed from quote.)

A friend is telling me that it is just a stock header only and that the converter is located near the rear before the exhaust. described as a wider diameter metal tube. I did see this but did not find what looked to be sensors running to it. what is this?

but he is also telling me this is another stock header and it is labeled on it's website as a "Headers w/ High-Flow Catalytic Converter"
(Image removed from quote.)

^so is that wider portion on the bottom the cat or no? (more importantly the top picture)? is it what the website says it is?

 

it is an exhaust manifold, with the catalytic converter bolted to it. look at the second picture. the roundish thing bolted to the bottom of the manifold is the cat. some cars it is part of the manifold assembly.

 depending on the make/model/year, the top sensor could be either an air/fuel ratio sensor, or an oxygen sensor. the bottom one is always an oxygen sensor.
 all obd2 cars have a sensor upstream, and downstream of the cat. this is how the computer knows how well the cat's working. generally these sensors have 3 or 4 wires, as they're heated, helping to get the computer into closed loop faster.

[CAP1]

Yes that is the catalytic converter and O2 sensors. ANY passenger vehicle built in 1996 and after will have sensors before and after the converter. The actual placement of the equipment on the vehicle will vary, but the converter will ALWAYS be between the O2 sensors.

on many 4 cylinders, the cat is just off the manifold such as pictured. it helps keep the cat hot enough to keep it working more efficiently.

 the sad part is that i still see people....even kids.....that think it's a good thing to take the cat(s) off of their car. they don't realize that todays cats rob no power whatsoever.

[MaSonZ]

 the sad part is that i still see people....even kids.....that think it's a good thing to take the cat(s) off of their car. they don't realize that todays cats rob no power whatsoever.

didnt know this. CAP, you never cease to amaze me with your knowledge   

[bagrat]

  Thanks guys I had a feeling I was in the ballpark with these images. It throws me off when people tell me wrong info with all the confidence in the world (as my bud did ).  

Also in attempt to better preserve my car for a few years, I was contemplating to put an after market high flow converter on (replace the 1st pic with the 2nd). I've read higher flow= less resistance causing less work on the engine  (less work sounds good) and better mpg, but on the other hand that it will screw up "back pressure" the engine is designed to compensate for and actually make it worse...I dunno but I'm getting that if it ain't broke don't fix it feeling.

Any thoughts?

[MaSonZ]

i wouldnt mind replacing my cat with a high flow for better MPG, i havent heard the theory of back pressure though..

ciouple years back my brother replaced his two cats with one high performance and had no issues what so ever so i cant imagine replacing one with one would be an issue....

[gyrene81]

you would have to get your onboard computer "re-tuned" to adjust for the change. in some it's as simple as disconnecting the battery for a period of time, for others it requires a technician to do it properly.

[CAP1]

Thanks guys I had a feeling I was in the ballpark with these images. It throws me off when people tell me wrong info with all the confidence in the world (as my bud did ).  

Also in attempt to better preserve my car for a few years, I was contemplating to put an after market high flow converter on (replace the 1st pic with the 2nd). I've read higher flow= less resistance causing less work on the engine  (less work sounds good) and better mpg, but on the other hand that it will screw up "back pressure" the engine is designed to compensate for and actually make it worse...I dunno but I'm getting that if it ain't broke don't fix it feeling.

Any thoughts?

as long as you're not running a turbo, getting rid of backpressure can only be good. allowing your engine to exhale more easily, allows it to inhale more effeciently, thus gaining a better atomization of the air/fuel mixture. this will increase power, and mileage. it's a win/win/win really. and if your cat's got over 100k on it, you'll notice a good difference. if you do this, install new sensors with it.

[CAP1]

you would have to get your onboard computer "re-tuned" to adjust for the change. in some it's as simple as disconnecting the battery for a period of time, for others it requires a technician to do it properly.

obd2 computers do what ford's eec4 system was doing back in the 90's. it learns. it does it better though....simply change out the cat, and sensors, and drive....let the computer have some time to see the new "normal", and it'll make the adjustments. 

[MaSonZ]

I love you cap... in a straight way.

The theory is my car being a ford escort with mazda badging it should take like a ford, no?

[CAP1]

i wouldnt mind replacing my cat with a high flow for better MPG, i havent heard the theory of back pressure though..

ciouple years back my brother replaced his two cats with one high performance and had no issues what so ever so i cant imagine replacing one with one would be an issue....

 while those of us working in the bays know what your brother did, was a good thing.....be very very careful removing any emissions control device. technically speaking, if he were stopped in a roadside check....and they do have roving emission test centers in nj.........and the people checking his car were smart enough to realize it should have 2 cats, rather than 1........it could equal serious fines for him. epa's touchy about people questioning em. or making improvements on them.

[CAP1]

I love you cap... in a straight way.

The theory is my car being a ford escort with mazda badging it should take like a ford, no?

what year was yours again? i know 94 proteges use the eec4 control system. if you're newer than 96, it'll learn.

 also....what fixed it from the last problem?

[gyrene81]

obd2 computers do what ford's eec4 system was doing back in the 90's. it learns. it does it better though....simply change out the cat, and sensors, and drive....let the computer have some time to see the new "normal", and it'll make the adjustments. 

ah ok, was told differently by a mechanic that i no longer use. i wonder if my 04 pontiac alero has that capability  i'd like to switch out the air filter for a k&n setup, toss in some hi-perf plugs on competition wires, maybe even some hi-perf ignition modules if they exist, and pop on some headers and hi-flow cat...the 3400 v6 is perky but sucks gas like a ford pickup.