Katalisator Problem

[apsaauga]

Hi, for quite long period i was experiencing lack of power with my IS 200, 73k on the clock. Only now one engine specialist suggested me to check the katalisator. Indeed it could be the reason, also sometimes i have egg smell in my car and some burnt smell, it also shows that it can be the katalisator problem. So for new one lexus asked me 750 EURO without VAT. So hell no! I think about aftermarked one (~200EURO without VAT), but it will need some changes in pipes lenght and so on. What do you think? Will be any problems with aftermarked one? May it be the main reason of not smooth and very very slugish ride? It realy was good half year ago, and suddenly it changed! Also could smaller(~ 4 cm) decoration of exaust pipe cause katalisator to choke?

Thanks in advance

[Rob]

the egg smell is normal for a katalisator, this happens when it is heating up, but the smell should go away once the engine is hot.

the pre kats ( the ones in the engine bay) are known to break but this is normally a gradual effect and not a sudden one, if these break down then it will reduce the performance.

for replacement kat - speak with dave ( pro-lex) as i believe he has some soon.

as for the decoration on the exhaust - i am assuming u mean on the exhaust tip? that should not really make a difference unless it blocks the exhast a lot - got a picture so see exactly what u mean or a better description?

[ColinBarber]

I would get the pre-cat checked, it is probably the problem rather than the main one.

[apsaauga]

The lack of power came with some time, stronger and stronger, so it is as You say, not a sudden effect, i must said not right in the topic.

for replacement kat, i am from Lithuania, hope You know where it is:), so getting one prom pro-lex would be difficult, however interesting.

as for the decoration on the exhaust, yes i mean exhaust tip. I have no pictures here, but i can explain. The chrome tip, that was on the exhaust pipe had 4 cm smaller hole than the stock pipe, i mean 2 cm from one side, so around gets 4 cm. I noticed that car got sluggish, so after 2 months i took it of. I think someone said it also could be the reason why it choked, because the exhaust system is very sensitive?

[apsaauga]

I would get the pre-cat checked, it is probably the problem rather than the main one.

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Pre-kat is one of 2 in the front and the main is in the center of the car?

[ColinBarber]

That is correct.

[apsaauga]

Thank You. Will it be OK, if i change bad pre-cat with universal one, not Lexus or for lexus? It will need minimal fitting changes. And how about situation it there will be one original and one changed with aftermarked?

[TonyGoose]

Thank You. Will it be OK, if i change bad pre-cat with universal one, not Lexus or for lexus? It will need minimal fitting changes. And how about situation it there will be one original and one changed with aftermarked?

←

The pre-cats are part of the exhaust manifold.

You can either replace the mainfold or have the pre-cats cut out.

[apsaauga]

SO pre-cats can be cutted out? Lexus said they can't, Check lamp will blink all the time, revs will be unstable on neutral, more fuel will be needed and noise will be louder. So what is the truth? Has anybody cutted them out here?

[ColinBarber]

quite a few people have then cut out. If you have the TTE supercharger it is recommended they are removed because they can fall apart with the extra heat.

The engine check light will not come on. However it takes a long time for the main cat to heat up and work correctly so for the MOT in the UK which checks emmisions you have to take the car on a long run before the check.

[apsaauga]

I don't have a supercharger:) so Would You recomend me to cut them out? Or put aftermarked one? And what about power? Will it increase a bit? Noise will be much louder? And what about fuel? how much it will increase? Help would be appreciated, because i have to decide what to do till friday, i have reservation in exhaust system servise.

thanks for your attention

[ColinBarber]

Not sure if there are aftermarket ones for the IS pre-cat. Having it removed will be cheaper than having a new one fitted.

The cat is restictive and therefore power should increase when it is removed, although probably not very much on a standard engine. Fuel economy should also get slightly better.