Went To True Dual Exhaust On '90 Ls400

[harjp]

After seeing SKperformance's diagram of the exhaust system (below), I thought it would be fun to get rid of some of those sharp bends, multiple resonators, and the single pipe mid section.

the exhaust on mine looks like this 90-00

........|.|............... exhaust mainfold

.........T............... Y merge collector( really sharp angles and restriction)

.........|................ mid section

.........0............... resonator #1

.........|............... mid section

.........JL.............. another wide Y collector (same bad design)

....._ /..\ _........... rear intermidiate pipe

....0.........0..........resonators #2 with 90 degree inlets

....|..........|......... connecting pipe to mufflers

...{}........{}........ mufflers

.....\........./......... downfacing tips hidden under bumper

this gives you an idea of what it looks like under your car

an 01 and newer should have a few more options if you check www.luxurymods.com

I took my car to Chris at Scottsdale Muffler. He suggested using DynaMax Super Max mufflers and alloid-packed resonators. All-in cost was $525 -- which I think is a great price! (Midas charged me about the same for doing less to my F250. Don't go there!) Here's the job Chris did:

The car now sounds aggressive, but not loud. It has a rumble to it, but nothing crazy. You have to be outside the car or have the window down to hear anything more than a slight change (deeper) in tone. Performance-wise, it's a little more aggressive too. I'll know better when the outdoor temp drops below 110 degrees!

And here's my car looking all happy with her new exhaust system.

[SKperformance]

Not a bad job. Did they use aluminized or stainless steel piping?

$525 is ok as i have had $650 CAD quote for replacing all the piping up to the mufflers from the headers . This would involved remaking the first set of curves but you did get new mufflers and mine was to keep my L-sportlines.

If you reset the ecu you will have dramatic gains other wise it will slowly adapt over a week to the new freedom.

[harjp]

ECU. That's the computer, right?

Don't know about the piping, except that it was 2 1/4". Aluminized vs. SS -- what are the pro and cons?

By the way, I did the Lexls.com method of adjusting the TPS to bring my idle speed back to about 650 rpm. With no load, idle speed was around 200. Since then, every time I take the engine up to 4500+ RPMs on the road, my "check engine" light comes on. My battery was going bad, so I was hoping that was it. And after the new battery was in, the light stayed off for a day, but I didn't rev the car/engine up. Today, after I got the car back with the new exhaust, I was accelerating hard and the "check engine" light came back on. Any thoughts?

In any case, I'm heading down to the car to disconnect the battery for 90 seconds! "Dramatic gains" sounds good!

[SKperformance]

Aluminized will rust and break down much faster as well as being thinner causing more resonace inside the cabin.

Check the code by jumping the pins to find out what is the issue for sure.

[harjp]

I don't know how to pull codes. Is there a tutorial on that somewhere? What equipment do I need?

[harjp]

Well, that was fun! Re-set the computer and took her out on the freeway. The exhaust sounds even deeper, car had much more kick to her. She must be breathing better!

[SKperformance]

It basically works by taking a paperclip and shorting two pins on the connectors . Since you reset your battery you will have to wait until it stores another code as you erased the last one .

[harjp]

Where do you read the code? And which connector, which pins?

I search for a thread on this, but came up empty. If there's one out there that I missed, let me know and I'll keep searching.

[93ls400walt]

There are two ways. Under the dash or under the hood. Under the hood is much easier.

Near the front of the engine, on the drivers side is a black plastic box. Looks like a small fuse box. Open the lid and look under the lid for the diagram of the terminals.

Turn the ignition switch to on ( do not start)

use the clip or an electric wire to jump the TE-1 and the E-1 terminal

Be sure the wire or clip does not move and touch any other terminals. Could cause a problem.

Look at the CEL. It should be blinking.

A normal code will be a constant steady blink of a 0.25 sec duration

Abnormal codes will read 1 to 7 blinks for the first number then a short pause then blink 1 to 8 times for the second number in the code. If you have more than one fault code. It will start at the lowest number code first.

Don't worry if you miss a code, It will keep repeating untill you remove the jump wire or turn the key off.

Post your code/s. Someone will have a key chart.

[harjp]

Hey, thanks for that explanation! I appreciate it!

After the last re-set, the CEL has remained off. We'll see if it comes back on.

[corndog]

Heya harjp, Did the factory exhaust loop over the top of the independant rear suspension? Thanks for posting great pictures of the under carriage too. Also, whet the heck is a resonator? The name of it makes me think its stricktly a sound related device. Are there any catalytic converters on the car? Where do the o2 sensors go?

[SKperformance]

Look under your car and you will see it goes under the all parts of the car.

A resonator is a small muffler , cats are by the exhaust manifold on either side which is where the o2 sensors go.

[dfkd]

This is the original undercarriage...

[corndog]

Excellent picture, thank you.

[MarioC]

Wow your undercarriage looks cleaner than my kitchen!

Just curious as what you did to get it so clean?

MarioC

[SKperformance]

Wow your undercarriage looks cleaner than my kitchen!

Just curious as what you did to get it so clean?

MarioC

It is a prototype car picture taken by Lexus .

[harjp]

Look under your car and you will see it goes under the all parts of the car.

A resonator is a small muffler , cats are by the exhaust manifold on either side which is where the o2 sensors go.

Green = cats.

Red = o2 sensors

[Ross W.]

Wow! That looks really great. I was considering just replacing the mid pipe on my car, but I'm going to go with a full exhaust and maybe the S&S headers as well.

Thanks for sharing!