Cat. converter going bad and front suspension clunks

[1997eclipse rs]

okay when i get off the interstate and i downshift/let of the gas i get a really bad smell coming from somewhere its like sour is that my cat going bad?

second question in my front end i whenever i go over speedbumps or hit bumps it makes a reall weird sound kinda like a popping sound but not a popping sound?

3rd question im replacing all my pipping on my car this is pretty relivant to the first question if the cat is going bad.... but anyways how big should i re pipe the car and how many feet do i need for it because im going to do a cat delete

please and thanks in advance for the quick responses and sorry if this is posted somewhere else!

 

[FalleN4ng31]

3rd question im replacing all my pipping on my car this is pretty relivant to the first question if the cat is going bad.... but anyways how big should i re pipe the car and how many feet do i need for it because im going to do a cat delete

This doesn't really make a lot of sense. You're planning on fabricating an exhaust entirely? That's an awful lot of work when there are a slew of aftermarket options available. (And don't take this as an insult, but you don't sound like you've fabricated anything before.) You can do a cat-delete with any aftermarket exhaust, really. It's just a matter of bolting in a test-pipe where the cat used to be.

 

[gsexxx]

Perhaps one of your front shocks is blown?

If I were you, I would pick up a used 3" exhaust w/ dp for cheap and take the section of the exhaust that has the cat to an exhaust shop and have them cut out the cat and weld in a straight pipe.

 

[slickers111]

http://www.dsmtuners.com/forums/420a-bolt-tech/6416-question-stock-exhaust.html

Searching wonders.

If youre just cutting off the cat, and putting a pipe on, I'd cut it safe at 1 1/2 ft of pipe. The pipe itself shouldnt be more than $10.I dont know if you are planning on welding it completely, or just clamping it.

Just make sure its sealed good. N/T's sound ugly with exhaust leaks.

As for the suspension, the shock could be blown, and the rubber seats could be shot. It the rubber isnt there, it will give you the clunk sound.
New shocks are $76 at AutoZone each, without the spring.

I recommend KYB AGX 8 way shocks/struts. But theyre kinda expensive.

 

[1997eclipse rs]

okay i had someone check the shock they said my right front is blowin getting a new one today . and all im doing with the exhaust pipe is getting so many ft in a straight pipe not sure how big because my other pipping is really rusty and looks like its going to fall apart i have a guy that bends and does it for free and im just buying an apexi n1 for about 25 dollars? does that sound like it would work ?

 

[gsexxx]

okay i had someone check the shock they said my right front is blowin getting a new one today . and all im doing with the exhaust pipe is getting so many ft in a straight pipe not sure how big because my other pipping is really rusty and looks like its going to fall apart i have a guy that bends and does it for free and im just buying an apexi n1 for about 25 dollars? does that sound like it would work ?

From what you described, it sounded like the shock was the issue . You found a apexi n1 exhaust for $25? That's a steal. I am assuming it's a cat-back and doesn't have a dp? And yeah just have an exhaust shop cut out the cat and weld in a straight pipe to replace it. I believe you will get a code when removing the cat so do you have link?

 

[1997eclipse rs]

i mean the shock didnt really bother when driving on the interstate or anything bro but when you hit bumps and stuff it was annoying -__- and im redoing all of the exhaust from manifold back is 2.5 to big or can i go to 3? and yah 25.00 its andysautosport.com its usually 45.00 its just the tip though ill post the link here in a second

 

[1997eclipse rs]

95-99 Mitsubishi Eclipse Mufflers from Spec D at Andy's Auto Sport there you go bro!

 

[TurboLaserRS]

If the car has a rear o2 sensor it will throw a PO420 "catalyst efficiency under threshold" or if the o2 is not even in the exhaust it will throw a PO134 "02 sensor circuit no activity detected".

If you put a spark plug non fouler in the o2 bung and then screw the o2 sensor into that, it won't eliminate the check engine light completely but it will be a lot more intermittent. Any OBD2 car is going to be reading the rear o2 to make sure the cat is doing it's job as per federal emissions regulation and I really don't think paying $585.00 for tuning software (LINK) is worth it just to turn off the check engine light.

There are also resistor mods that have been done with other cars for cheap that trick the O2 sensor into seeing a proper voltage and telling the ECU that everything is honkey doorey.

Basically either replace the cat, chop it off and ignore the night light, or find the proper resistor to wire into the o2 to trick it.

 

[1997eclipse rs]

my check engine light is already on i have a couple sensors are bad im working on fixing them because the idiot that owned it before me didnt take care of the poor car :/ and i just cover up the little light with a picture of my little niece haha

 

[gsexxx]

If the car has a rear o2 sensor it will throw a PO420 "catalyst efficiency under threshold" or if the o2 is not even in the exhaust it will throw a PO134 "02 sensor circuit no activity detected".

If you put a spark plug non fouler in the o2 bung and then screw the o2 sensor into that, it won't eliminate the check engine light completely but it will be a lot more intermittent. Any OBD2 car is going to be reading the rear o2 to make sure the cat is doing it's job as per federal emissions regulation and I really don't think paying $585.00 for tuning software (LINK) is worth it just to turn off the check engine light.

There are also resistor mods that have been done with other cars for cheap that trick the O2 sensor into seeing a proper voltage and telling the ECU that everything is honkey doorey.

Basically either replace the cat, chop it off and ignore the night light, or find the proper resistor to wire into the o2 to trick it.

I wasn't suggesting link in order for him to clear the code he will get when removing the cat. I was just seeing if he had link or another kind of tuning software. I don't think he was aware that he would get a code when removing the cat. Good info though

 

[TurboLaserRS]

I see what you meant now. But if I remember correctly there is a way to turn off rear o2 monitoring via link which is what I thought you were referring to. He could clear the code himself with any handheld scanner if he wanted to.
On my Grand AM for instance it sat for about 2 months without me driving it. About 2 weeks ago I took it on vacation as it gets 30mpg and the check engine light was off for the entire time- around 900 miles before it came back on for the PO420 code. I have the spark plug non fouler installed.

 

[1997eclipse rs]

thanks for all the information on it i didnt know were the o2 sensor was on this so i didnt know if it would kick the light on or not not that it matters

 

[slickers111]

Why not stop at a junk yard?

Im sure theres N/T's out there with an exhaust on it. Blown motor cases. Too much F&F.

We got 3 N/T's with header back exhausts on it.

And as for the size, Id stick with a 2.5 inch, and what ever output you want. 3 inch hurts the backpressure.


Be sure to post up a sound clip of the exhaust when its done!

 

[1997eclipse rs]

i just need to buy the pipping at max 50 bucks and yah i wasnt sure if 3 inch would hurt the back preassure and i sure will! and i want all new pipping not used pipping !

 

[pointblank9957]

If this is a 98/99 you could just flash it and remove those trouble codes completely from the ECU (the rear o2 and cat). Thats what i do, saves fristration.