'99 LS400 Catalytic converter
01-11-14, 03:27 AM
#1
Intermediate
Thread Starter
'99 LS400 Catalytic converter
I've got a '99 LS400 with 240,000km... If I gutted both the cat converters would this be of any advantage to have free flow ?
01-11-14, 09:53 AM
#3
Lexus Champion
If you "gut" them, you will lose performance, fuel mileage, as well as emissions compliance - in order to gain any performance advantage from "gutting " cats, you would have to reprogram the ECU, and no one has ever successfully broken the encryption on LS400 ECU's - so this is a very bad idea all around, you lose in every category and gain nothing!
If you want high performance, get a Nissan GT-R
01-11-14, 10:49 PM
#6
Intermediate
Thread Starter
No!! - the LS400 cats are very well designed and very high performing (free flow) and very reliable (and very expensive)
If you "gut" them, you will lose performance, fuel mileage, as well as emissions compliance - in order to gain any performance advantage from "gutting " cats, you would have to reprogram the ECU, and no one has ever successfully broken the encryption on LS400 ECU's - so this is a very bad idea all around, you lose in every category and gain nothing!
If you want high performance, get a Nissan GT-R
If you "gut" them, you will lose performance, fuel mileage, as well as emissions compliance - in order to gain any performance advantage from "gutting " cats, you would have to reprogram the ECU, and no one has ever successfully broken the encryption on LS400 ECU's - so this is a very bad idea all around, you lose in every category and gain nothing!
If you want high performance, get a Nissan GT-R
01-11-14, 10:50 PM
#7
Intermediate
Thread Starter
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01-11-14, 11:54 PM
#9
Lexus Champion
yeah, 240,000 km is nothing for LS400 cats - they will easily go 450,000 km 
the only exception is if you lived in a place where they salt the roads and they were getting a hole in them
there are PLENTY of better things to spend your money on, like every piece of rubber under your car (bushings, ball joints, etc.)
the only exception is if you lived in a place where they salt the roads and they were getting a hole in them
there are PLENTY of better things to spend your money on, like every piece of rubber under your car (bushings, ball joints, etc.)
Last edited by LScowboyLS; 01-11-14 at 11:57 PM.
01-12-14, 01:54 AM
#10
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01-13-14, 06:30 PM
#12
Intermediate
Thread Starter
01-13-14, 07:01 PM
#14
Intermediate
Thread Starter
yeah, 240,000 km is nothing for LS400 cats - they will easily go 450,000 km
the only exception is if you lived in a place where they salt the roads and they were getting a hole in them
there are PLENTY of better things to spend your money on, like every piece of rubber under your car (bushings, ball joints, etc.)
the only exception is if you lived in a place where they salt the roads and they were getting a hole in them
there are PLENTY of better things to spend your money on, like every piece of rubber under your car (bushings, ball joints, etc.)
Everything I do now I would like to do for improved fuel economy.. In the 4 years since I bought it, petrol prices have doubled to $1.60 per litre .....
I thought if anything, gutting the cat con's it might run a bit leaner... I have an air/fuel gauge insert welded in the header pipes.. just haven't put the gauge in yet... also an EGT insert...
I also have a Jaycar digital fuel adjuster... its about 128 way points and splices into the intake air temp sensor... Auto speed tested it on our model LS400 and said it worked a treat...
http://www.autospeed.com/cms/A_2576/article.html (read parts 1,2 and 3 in top lines )
01-13-14, 07:15 PM
#15
Done all that Mr LScowboyLS.. Bilstein shocks, ball joints, Rola control arm bushes, reco'd steering rack, customs 24mm solid rear sway bar, braided steel brake lines, 225/55/16 Directional tyres... 42psi, ... It steers and drives like new.. no clunks or creeks...
Everything I do now I would like to do for improved fuel economy.. In the 4 years since I bought it, petrol prices have doubled to $1.60 per litre .....
I thought if anything, gutting the cat con's it might run a bit leaner... I have an air/fuel gauge insert welded in the header pipes.. just haven't put the gauge in yet... also an EGT insert...
I also have a Jaycar digital fuel adjuster... its about 128 way points and splices into the intake air temp sensor... Auto speed tested it on our model LS400 and said it worked a treat...
http://www.autospeed.com/cms/A_2576/article.html (read parts 1,2 and 3 in top lines )
Everything I do now I would like to do for improved fuel economy.. In the 4 years since I bought it, petrol prices have doubled to $1.60 per litre .....
I thought if anything, gutting the cat con's it might run a bit leaner... I have an air/fuel gauge insert welded in the header pipes.. just haven't put the gauge in yet... also an EGT insert...
I also have a Jaycar digital fuel adjuster... its about 128 way points and splices into the intake air temp sensor... Auto speed tested it on our model LS400 and said it worked a treat...
http://www.autospeed.com/cms/A_2576/article.html (read parts 1,2 and 3 in top lines )