Possible Cat Blocked On My R34 Gtr?

[K33P UP]

Hey Everyone,

i thought i would see what everyone else thinks on this issue with my GTR, since its the weekend all the shops are closed so i cant take it anywhere until next week

This is the problem i am facing, since last night my car hasn't been boosting properly (going to 0.4 bar when it normally goes to 0.8) my exhaust note inst as loud as it normally is when your pressing the accelerator. It all happened when i hit max boost and high revs (7000rpm) it just cut out on me, boost was down and exhaust note was very different all of a sudden. The engine still revs but its very doughy and you can hear the turbo spool a little but not as much. could it be a possible blocked cat? not sure what else it can be, i look at the hoses on the intake and BOV and all seem to be fine.

Any ideas where i could take the car on the gold coast if its not a cat issue?

[Nee-san]

Drop the cat off the exhaust and take it for a drive.

make sure you check inside the cat itself for damage and obstruction.

hopefully you haven't blown a turbo.

report back.

[SiR_RB]

sounds like a turbo has gone bye bye u might find bits of exhaust wheel in ur cat when u drop it down.

[K33P UP]

my car is still making power (0.4 BAR boost) but the car is just struggling to get there and the exhaust is very quiet, if it was a turbo wouldnt it make no boost?

Edited April 16, 2011 by K33P UP

[K33P UP]

are they a ceramic wheel in the turbo?

[K33P UP]

also another thing to add is that both inlet pipes are sucking and the main hose to the plenum is making a fair bit of flow. so the motor is getting air.

if it was the exhaust wheel in the turbo's the intake should be producing flow correct? also there doesnt seem to be any oil usage just alot of fuel dumping out

Edited April 16, 2011 by K33P UP

[Hanaldo]

my car is still making power (0.4 BAR boost) but the car is just struggling to get there and the exhaust is very quiet, if it was a turbo wouldnt it make no boost?

Well if you've only blown one turbo then the other one will still be boosting.

Check cat first, quick and easy.

[DVS JEZ]

Drop the cat out and have a good look at it.

[Fullboost_Performance]

Load up the car on a dyno or going up a hill and see if the cat starts to glow red. If so its a blocked cat, had same issue with mine when it was stock

[K33P UP]

thanks for your help everyone, im going to take it to an exhaust shop and see if we can get this cat looked at as a replacement is any steel 100 cell cat ok?

[Nee-san]

Yes, but make sure its big enough.

Honestly, if you can drop the cat yourself at home it will save you money.

It's literally 4 bolts under the car.

[MrStabby]

Well if you've only blown one turbo then the other one will still be boosting.

The second turbo will spin, but wont make any boost as the air blows back through the compressor of the dead turbo.... So since OP is getting boost, its not an exploded turbine.

[3LGODZILA]

Load up the car on a dyno or going up a hill and see if the cat starts to glow red. If so its a blocked cat, had same issue with mine when it was stock

lol wouldnt it be much easier and safer just to drop the cat and look? if a turbo is half rooted (also being ceramic) the last thing u wanna do is spin the engine at 7000+ rpm

[Fullboost_Performance]

lol wouldnt it be much easier and safer just to drop the cat and look? if a turbo is half rooted (also being ceramic) the last thing u wanna do is spin the engine at 7000+ rpm

Probably not, loading up meaning 2500-3000rpm up a hill in 4th, so its under load, if the cats blocked doing this for about 10-15 seconds will make it glow, seems easier than jacking the car up, and taking the cat out...

[3LGODZILA]

Probably not, loading up meaning 2500-3000rpm up a hill in 4th, so its under load, if the cats blocked doing this for about 10-15 seconds will make it glow, seems easier than jacking the car up, and taking the cat out...

each to their own, im just saying if theres any chance it could be the turbo i wouldn't be boosting it. when i did my standard turbo the bearings went causing the impeller to spin out of balance (very slightly) causing it to just nip the sides of the housing which chipped tiny bits of the blades off, mind you as soon as it blew i didn't boost it at all on the drive home but if i did im sure it would have just smashed apart the impeller wheel completely and if it were a GTR theres a good chance it will go through the intake side.

[K33P UP]

yep it was definetly the a blocked cat, here is a picture of what it looked like from the front. pretty impressive i must say.

so now i have a new stainless high flow 200 cel cat, the car has never run so good..... makes me think the cat has been blocked since i bought it. best $300 i have spent yet!

thanks for your advice everyone

Regards,

Dom

Edited April 20, 2011 by K33P UP

[DVS JEZ]

Awesome. Probably one of the easiest exhaust jobs too.