S&S headers on 2004-2006 LS430

[322432]

Has anyone installed s&s headers on 2004-2006 LS430? If so, curious as to how things went and any recomendations, ect.
Thanks
Keith

 

[JBrady]

Hey Keith, welcome to Lextreme.

I am unaware of anyone but a few are considering. It should be a direct fit since the GS430, SC430 and LS430s (2001-2004 and should be 2006 on the LS430) share the same part number for exhaust manifolds. They are a direct fit for the GS430 and SC430 so it is expected for the LS430. You may need to extend the wires for one or two of the oxy sensors but otherwise just like replacing stock manifolds. Access is much easier on 2001+ cars since they went to the single tube stock manifolds and that makes removing the stockers much easier (that is the most difficult part of the job).

Keep us posted.

 

[322432]

JBrady
Thanks for the comeback and welcome. I just bought a 2004 LS430; not really interested in a lot more horsepower, although more torque is always good. I just like for my engines to breath and scavenge reasonably well because it's a hell of a lot better and adds to longevity, in my opinion. What are others doing with the heat shields after header install? I'll probably keep the stock Y pipe and replace the center cat, muffler, or whatever is there, with a straight pipe of either 2.25" or2.5" hoping to create a venturi effect and lower pressure to help scavenge the cylinders Not sure what I'll do from there back. I'd like to keep the stock tail pipes if not too restrictive. The muffler shops here do not weld stainless, although other shops do, but cannot bend pipes. The rear mufflers will be replaced with dual outlets; this is just for looks for me. This bring up another question: I have always gone oversize on mufflers and whatever is behind them, my theory being that mufflers and bends are restictive. I would appreciate your opinion on my thoughts.
Thank you very much
Keith

 

[JBrady]

I would keep the entire stock system with the possibility of the final mufflers. The stock Y pipe is just fine and is probably tough to improve on for best torque curve. Unlike the LS400s that had very restrictive center mufflers and less than great second splitting Y pipe... the LS430s use a system that is more like the GS400s with a better second Y section and straight through resonators instead of center mufflers.

There is no need to replace the center cat with a straight pipe as that cat flows well and the piping before and after is 2.36" which supports your target power levels.

The stock heat sheilds will not fit over the headers but a set from a GS400 will although there are no mounting brackets for the attachment bolts. Functionally the ceramic coating on the headers suppresses enough heat as to not be a problem running without the sheilds.

 

[322432]

Thanks again JBrady for your input. What about the EGR on the 2004 LS430? Can it be deleted, and if so, will Lextreme's delete kit work on it? Any ideas appreciated.
Thanks
Keith

 

[spf_lexus]

Yes, I have Lextreme's EGR delete and it works flawlessly. 3 plates, 1 for header and 1 for rear of manifold and third is for side of manifold. Once you'v ripped all the EGR equipment off a supplied resistor (10k I believe) is bent into a "U" and slid into the slots in your EGR plug. This tells computer it's still functioning once it's removed. 2 years on my 1991 and never had a check engine light/issue.

 

[322432]

Headers installed

Got the '04 LS 430 back with S&S headers installed; had a shop do it as I had not the time. I may have lost a little low end, but am sure that mid range is stronger and the motor seems smoother. I bought new Denso O2 sensors, precat, for both sides, as well as new nuts for everthing; had to replace one stud. The red triangle and VSC- track off lights come on within about a minute of starting. MY OBD II code reader shows no codes. anybody got any ideas of how to fix this. Have aready tried the battery disconnect; it was disconnected during install also.
Thanks in advance
Keith

 

[JBrady]

Got the '04 LS 430 back with S&S headers installed; had a shop do it as I had not the time. I may have lost a little low end, but am sure that mid range is stronger and the motor seems smoother. I bought new Denso O2 sensors, precat, for both sides, as well as new nuts for everthing; had to replace one stud. The red triangle and VSC- track off lights come on within about a minute of starting. MY OBD II code reader shows no codes. anybody got any ideas of how to fix this. Have aready tried the battery disconnect; it was disconnected during install also.
Thanks in advance
Keith

Keith, congrats on getting the headers installed. I am surprised that you may have lost any low end. In all the S&S installs I have heard about no one has reported this. After a week or so of driving please give a full report. I am also interested in seeing pictures of the removed manifolds. Obviously if the headers bolted in they have the head and cat flanges in the same locations that all Lexus sedan V8s have had since 2001.

Regarding the red triangle and trac off lights... strange. No codes. I am leaning towards a bad connector or wire from the install or possibly a coincidence. If a connector was not connectd or not completely re-connected or a wire was not secured and has touched hot exhaust parts there may be an issue. This could also be causing a low end torque issue if the ECU has sensed a problem. Your car should be noticeably faster.

Keep us posted.

 

[322432]

Not able to post pics, but stock manifolds exactly the same as in the pics of the tread you referred me to; headers fit very well- had to hog out one bolt hole on cat bolt up. I also had new factory manifold gaskets and before and after cat gaskets as well as the new O2 sensors. I bought a sensor for the pass side for the drivers side, and one with longer wires-4015- for the pass side.
I did get a code today-P0300- random misfire multiple. I have not driven the 430 for a month or more as it has been in the paint shop. Anything feels slow compared to my pumped up Duramax. When I get a chance, I'll pull the skid plate or whatever you call it, and check the O2 wiring and connections.
Thanks for all the help
I'll keep you posted
Keith

 

[JBrady]

Not able to post pics, but stock manifolds exactly the same as in the pics of the tread you referred me to; headers fit very well- had to hog out one bolt hole on cat bolt up. I also had new factory manifold gaskets and before and after cat gaskets as well as the new O2 sensors. I bought a sensor for the pass side for the drivers side, and one with longer wires-4015- for the pass side.

Sounds like you did the job the right way.

I did get a code today-P0300- random misfire multiple.

That is odd. Can't think of anything exhaust related that would cause that.

I have not driven the 430 for a month or more as it has been in the paint shop. Anything feels slow compared to my pumped up Duramax.

That makes sense. Comparing the torque of a naturally aspirated 4.3 liter to a turbo diesel V8 would make the low end feel... well... low.

When I get a chance, I'll pull the skid plate or whatever you call it, and check the O2 wiring and connections.
Thanks for all the help
I'll keep you posted
Keith

What with misfires and trac light problems it is hard to say if you are getting the actual power potential. I am curious to what is going on.

 

[322432]

After about a year of having the LS430 in paint and body shops, exhaust shops, and working away from home for six months, I have been able to drive it.I found that the codes were coming from a bare wire in the underhood wiring harness that was possibly damaged from the header install; fixed, no codes, great mid range torque and engine very smooth. I also replaced the rear mufflers with 50 series dual outlet flowmasters. It still is very quiet until you mash on it, and then not very loud. The flowmasters, not my first choice, but available and would fit for the custom tail end look that I wanted. Last weekend, I drove about 300 miles freeway in the rain, heavy enough that the rader cruise would not work, averaging about 70mph-24 miles per gallon hand figured. I was very plased.
Thank you J Brady, and others, for all the info and help.