MK1 LS400 HAS ANYONE REPLACED THE EMMISIONS RETURN PIPE

[chips229]

I spent nearly all day last Tuesday working on my LS 400,it took me most of the morning getting the cat off the car,all the bolts were rusty so i had to cut them all off,a 4inch grinner was to big and bulky to get to the bolts so i used a dremel..a right nasty job that was...so the cat was removed...
The bolts holding the emmisions pipe on the downpipe of the exhaust came undone easy,so did the bolts holding the end of the pipe going back into the inlet manifold,the single bolt supporting the pipe half way down the emmisions pipe came undone easy....Then i spent over a hour trying to get the emmisions pipe out from behind the engine...i tryed removing the pipe from the top and tryed removing the dam pipe from underneath the car...
I ended up breaking the pipe into 2 pieces,was still a pig of a job.
I then got a friend to cut the flanges off each end of the emmisions pipe and fill the holes in on the flanges...i put one stop end where the emmisions pipe bolted to the exhaust and the other where the emmisions pipe went to the inlet manifold....so job done i thought...
Now since driving the car for nearly a week,what ive noticed...
Plus points

Yea the exhaust blowing sound has gone...so its quieter to drive.
The response of the Throttle seems better

Bad points...

Its been warm over here for a few weeks now so its not been that cold over night,my point...the cars taking a age to warm up from cold now with no emmisions pipe feeding the inlet manifold with hot air...so come the winter whos know how long its going to take to warm up!!
I also notice that the cars is "pinking" around 1800rpm,which i didnt notice before,the emmisions pipe wasnt sounding that loud before i removed it so im sure i would have heard the "pinky"
So it seems as though the fueling has changed now that i have blocked off each end of the pipes.
As to my other posts,i can see now theres no rubber section in the emmisions pipe,just a flexy effort to allow the pipe to flex abit,its on the flexy bit where the pipe was blowing...
Any ideas guys
Im thinking of getting another emmisions pipe because the engine is using soooo much more petrol now...i was getting good mpg....now its down to around 13mpg...with the same driving style...
Its mainly shortish trips i do so the engine is always warming back up after standing for a while.
Sorry to write such a long post...

 

[Lexurious]

Try a ecu reset first. It may help.

 

[damon]

EGR Pipe assembly

From the description I just read above , this sounds like the topic of the day.

I have tackled this before and still have a scar on my forearm to prove it.

BTW: There was no need to remove the catalytic converter on my 94.

Here are my notes: Not much fun. The schematic showed only the 4 bolts referenced by Sooner in previous post as accessible from top or bottom. The real world throws you a nasty curve on a 94 LS, The one he describes as in the back of the block will consume most of your time. Above the passenger side cat you will find 2 studs which are easy to remove from below, towards the firewall on top of the engine there are 2 bolts which are a simple task , but the bolt on the back of the engine above the transmission, ( which did not appear on the parts schematic that I utilized as a reference) which Sooner discussed in his post, is an absolute bastard! Very little room between it and the firewall. I would by no means describe it's location as "visible".

3 bolts , 2 studs, 5 connection points total!

RESULTS: Sounds much better , but I had better see a mileage reward before my burns heal. Not kidding!!!

94 LS
Part # 25601-50010
price $116.14 USD from Carson Toyota

Current update: Sounds better but I do not seem to get any better mileage. Good news is that Premium is back below $2.00 a Gallon (3.78 Litres) in the US again.

 

[elhsupra]

If the 94 is like the 92 LS400.....
It has an EGR temp sensor that the computer uses to verify EGR operation. By blocking this off, you do get the benefits of no EGR but the ECU is now slightly confused. However you can use a resistor to correct the EGR temp being sent to the ECU. Look at the MkIV Supra TT EGR online to find an example or MR2 (http://www.madpsi.net/PMR2.htm)

 

[chips229]

Thanks for your replys,
Lexurious you say try a ecu reset,is that just a case of disconecting the battery for a set about of time? or is there a reset button on the ecu?
Ive only had the car a few months so im still finding my way around.
I meant to also say in my last post,if i was to fit a new emmisions pipe,how long roughly would it last until the pipe needs replacing again.Looking at the rust around the bolts holding the cat,Id say that this is the first time the cats had been taken off since new...so im thinking is this the factory fitted emmisions pipe?,if its lasted nearly 13 years id buy another replacement.
The next problem would be fitting the pipe without damaging it.

elhsupra,so as my cars running now,is it running richer because the return exhaust gases arent "watering down" the inlet fueling,so this resistor will cut the fueling back?

Chips.

 

[Lextreme II]

EGR pipe is a pain to replace. Its almost like taking the whole engine out due to the complexity of the pippings. When its cracked, you will hear exahaust leak and your Check Engine might or might not comes on. I had that problem. Replaced when i swap out the motor. Easiest way would be to do an EGR block stated earlier and replace the pipe when u do a major overhaul.

 

[chips229]

Thanks again for reply,because of the vast amount of fuel the car is using and the long time its taking for the engine to warm up,i think i will replace the egr with a new one...so wish me luck..
Thanks for all the feed back on this topic.

Cheers Chips.

 

[chips229]

Just a update,i bought my replacement EGR pipe last week,£87.09 with my uk Lexus club discount,daylight robbery at that price..
I waited until the weekend to fit it,spent 9 hours on Saturday fitting it!!!!
It took me all of half hour to remove the cat again and take to blank ends off and the rest of the time trying to squeeze the pipe down the back of the engine,after much cutting and bleeding to my hands to pipe was sort of in place.I had strong string tied to each end of the pipe to help pull the pipe into position,and the swearing and shouting coming from underneath the bonnet(hood) was unreal...i would have took on anyone the mood i was in LOL.
The Lexus garage fitter i was talking to when i picked the pipe up said if i want the pipe to last,i must put the bracket bolt in to secure it or it wont last long...i got the pipe bolted inplace but couldnt get the bracket bolt in place....until today.I went out and had another go this afternoon,i took the top pipe off from the inlet manifold and managed to bolt the bracket bolt in,only to have one of the inlet bolts holding the pipe to the manifold break off....more swearing...got the stud out after a while...all bolted up and ready to start the engine,only to find the top flange blowing...so after another refit of the top pipe the jobs done.....
So now the cars warming up quicker from cold and using less fuel....i knew i work get there in the end..im not one to give up,and at £116 a hour Labour at Lexus it was worth the trouble...
In all my years working on my own cars....THIS HAS TO BE THE WORST JOB I HAVE EVER DONE...EVER!!!
Good luck anyone else who tries it.