i have a 2002 5speed that looks to have way too many cats in the exhaust pipe. theres one big one thats the farthest back and then 3 smaller looking ones going back into the engine. i have no idea what they are and am interested in redoing my exhaust system soon.

 

4.0? Sounds normal to me.

 

the one biggest one farthest back is your muffler

 

well i know where the muffler is, but theres 4 things in between the engine and the joint in the pipe, right behind the catalyc converter. i just dont know what the other things are, if they are smaller cats or if they serve some other purpose

 

The newer trucks have 4 cats, I believe. Not sure why, though.

 

My 07 4.0 only has the 2 cats at the firewall

 

My 2001 has 4 cats. It's the norm, Ford's way of making that thing EPA legal.

1 right after each header. 1 before the y pipe, 1 after the y pipe, 1 before the muffler (I think thats correct)

 

And they are all high flow cats.

 

2 pre cats on the ypipe and 2 main cats

 

There are different configurations for different years. (gotta love ford sometimes)

My 06 has three. The two front ones are pre cats. They pre heat the exhaust before it goes into the main cat.

Most of these modern cars now-a-days have 3 or 4 02 sensors too. The front two are *before* the pre-cats. And the last 1 or 2 are *after* the last cat. It tells the PCM how the cats are performing.

Anything down stream of the last 02 sensor/s are mufflers or possibly resonators.

Rich

 

resonators anyone?

 

I was just speaking in generic terms. I've never seen one on a ranger. Usually you'll only see them on high end cars or cars where they are trying to have a certian exhaust note. (like our caddy eldo)

 

I've cracked open the pipe on my 01 4.0 and all 4 are cats, no resonators.

 

Guess for 07 they went back to only 2 cats.

 

2007 V6's still have 4 bricks, 2 in each housing.

 

My 04 had 3...