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Is My Cat Converter On Its Way Out

NFSR33

By NFSR33,
in Engines & Forced Induction

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NFSR33 Enthusiast

NFSR33

Posted
Posted

hey everyone,

let me set the scene.....recently my car has been makin noises, like the car is struggling, but can only been heard through exhaust..

now, it only happens after about ten minutes of driving (when the cars warmed up) and usually at low RPM or when the cars travelling at below 60....anything above and the car sounds fine..

my initial reaction was that the spark plugs were going, so i got a service and tune and the guy siad mechanically its fine (engine wise) which leads me to the conclusion that is an exhaust fault...

would this be the cat converter going on its way out?

has anyone had similar problems?

i have to drive to melbourne over the long weekend coming up so i wanna make sure its running perfectly!!

thank you!!

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NFSR33 Enthusiast

NFSR33

Posted
  • Author
Posted
an exhaust shop will be able to give you a proper diagnosis.

tap the cat to see if bits are rattling.

cheers mate

the only day i have off is sundays and no exhaust places down my way are open then, so time management is an issue.

plus, if i take it to an exhaust place without knowing myself what the fault is then im more likely to get scammed.

(if i go and say i THINK my cat is going, they will just replace it whether it is or not...haha)

i tapped the cat converter and couldnt hear anything rattling..

may be starting to block up tho

Thanks :wave:

Eug Grand Master

Eug

Posted
Posted

what kind of noise is it?? the components in an exhaust (cat & muffler) do degrade after a while, and especially so if you've been running rich

if you are able to, unbolt the cat and have a look for yourself

GTS4WD Grand Master

GTS4WD

Posted
Posted (edited)
why not just unbolt the cat....if it is flanged that is.

its a 10min job. and u can be 100% sure on whether it is the problem

You may need to soak the nuts and bolts in WD40 for a while.. And breaker bars are a good idea too. Save yourself a whole heap of effort, trouble and problems..

Edited by GTS4WD
R338OY Veteran

R338OY

Posted
Posted

Correct me if i'm wrong, but i don't see why a rooted cat would be restictive at low rpms and get better at higher rpms. Wouldn't it be crap regardless, and more so at higher duty?

Does the car backfire often?

Anyhow, it's better to eliminate it- so pull off the cat.

NFSR33 Enthusiast

NFSR33

Posted
  • Author
Posted
you say it starts struggling 10mins into the drive... do you get the "check engine" light? if there was something truly wrong with the exhaust im sure the "Exhaust" symbol would light up

yeh it seems to be after the car has warmed up....for example, i could be parked at the lights and it feels like the cars dropping out but only for a split second..like, the RPM gauge will go from 1000RPM to 700RPM then back up within a second, but it does that continuosly until i reach above 80kms an hour.honestly it is so hard to explain so sorry for the confusion..

i just got the exhaust put on, like in a matter of two weeks..

its been through services and tunes, so i know it isnt running rich, thats why i am assuming its the cat, but the Symptoms (so to speak), are a bit different than usual cases...

Yet to take cat off,but will friday..called in a sicky!!! :P

cheers!!!!!!

NA_Goodness Grand Master

NA_Goodness

Posted
Posted

I thought when the cat's going, it rattles when the car is cold, then stops when it has warmed up? Thats what mine is doing, although when you hit it, it doesnt rattle. I'm very confused now... I've lost so much power, and the car feels restrictive to drive, and it all happened around the time the clicking started. Any ideas?

scotty014 Veteran

scotty014

Posted
Posted

i get a rattle in mine when its cold but when warmed up its fine it happens between 2 and 3000rpm ill probably take it to an exhaust shop for them to look at it and see what they think. but then ive herd its normal for N/A r34's like how N/A r33's have that rasp.

NFSR33 Enthusiast

NFSR33

Posted
  • Author
Posted (edited)

update............

ok, this is really really annoying me...

been to the mechanics twice, paid for two different services and the problem still exists..

my r33 is misfiring, at low RPM and at Idle....does anyone know what could cause this...the longer i drive it, the worse it gets

- i have already got the spark plugs checked, ECU, Catalytic converter, full service and tune, O2 sensor checked, solanoid, basically everything....now, im due to go to the mechanics 2moro, but they are saying it may be the fuel injectors....

where as im leaning towards a vaccuum leak, hence the reason the misfiring is consistant during idle...

has anyone had similar problems...need help!!!!!!

Edited by NFSR33
Eug Grand Master

Eug

Posted
Posted
have you checked the coilpacks, it might be that.

agreed, i'd check those before injectors...

coil packs seem to be failing quite regularly now days that skylines are getting older.

remember that these cars are over 10 years old and yet we expect them to perform as if they have just come off the showroom floor.

NFSR33 Enthusiast

NFSR33

Posted
  • Author
Posted

update time....

so i took it down to my mechanic....got it looked again...(3rd time)

told him that i CAN only be two things, injectors or coils...as every other alternative has been checked and disregarded...

low and behold, its the coils...

but the bad thing - the price - $850 for set....

HOLY SHIT!!! :)

haha

car is booked in once again, for monday to get coils done..

will update if the problem is resolved...if not, get rady for alot of curse words.. :O

NFSR33 Enthusiast

NFSR33

Posted
  • Author
Posted
WHATEVER COILPACKS YOU'RE BUYING DONT BUY THEM!!!

http://www.skylinesaustralia.com/forums/Sp...99-t188698.html

splitfires for $499... doooo eeeeeeeeet!!!!

glad we can help

$499, for spitfires for an rb25de?

F U C K...!!!!!!! sorry about swearing

ive already got em ordered, exact same ones for $850 fitted..

im p'd off.... :down:

damn, i shoulda posted em earlier, woulda saved myself considerable amount of $$$

thanks for the help!!

and for makin me look retarded :) hahah kiddin..

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