Part throttle issue, as I get to about 1700rpms it just feels like it losses power. Now if I get it heavy throttle no problems cruising at speed also no problems . And I can't seam to turn on the trac. I also just did a egr delete thanking it might be related. Any ideas?

how does it idle?

probably is bad ECU capacitors. check out this thread,


https://www.clublexus.com/forums/ls4...capacitor.html

idles great, but I feel a tad low

drove the car again today and it only has the issue with 20% throttle or less with trying to increase speed slowly, wot good idle good and more the 20% throttle good. I haven't pulled ecu yet but is that your best guess?

thanks

It is a very known issue with our LS cars and is known to cause all sorts of problems such as the problems you are having. Even if it doesn't fix your problem you can bet you will save yourself a headache down the road. Think of it this way.... It's not if they will go bad, but when they will go bad because if they haven't been replaced you can bet your bottom dollar they will. If you replace them it should fix your issues but do this first!

ok the cars ive played with in the past have had the same issue dsm and 3000gt, like you said its not a if is a when

Have you checked for diagnostic codes?: http://www.lexls.com/tutorials/intro/codereading.html

that doesn't sound like a good plan, I don't know why folks feel the need to delete the EGR or the cats or anything else in the LS400 - unlike some American made cars, there is no "homemade engineering" that is gonna make your LS any better, and these backyard mods will likely make it worse!

I would stick to changing the turn signal bumper light lenses to clear or something like that, or perhaps a sound system upgrade of the head unit/CD player if you know someone highly competent that is not gonna screw up the Lexus factory wiring.

most any other "mod" is not gonna be an improvement in the long run, quite the contrary

Adding speedholes to the hood is actually one of the best mods you can do to an LS400. Just a few swings of the pickaxe and you're set!

dont forget about speedholes for the side fenders. lots of fresh air...lol

ive deleted my egr on all my cars for a few reasons, I don't like hot gases in the intake system, 2 cleans up the bay, and if the jdm didn't have them then we don't need them,
and as far as cats there can be big power left in the cats, on my frist 3000gt vr4 I picked up 45awhp just from removing erg and cats. now with that said turbo cars love more flow.

so that's why we do it

Since the EGR is just for emissions and it does dirty the intake system more I can see why that one. As far as the cats go, sure and FI car your going to see more results but on the LS400 it really does not help. Plus you are polluting the environment more putting out nasty fumes to the car behind you.

As far as your problem goes, throttle body, engine temperature sensor, etc... Need to look for codes and start having some parts tested. ECU, although becoming more prevalent, is the usually the last test / fix.

The LS400 was designed with the top engineers in the world! Countless research went into the making of our LS cars. I can see changing some visual things to suit your taste but the egr not only provides the proper emissions but it actually increases gas mileage. Also if you have deleted your cats your o2 sensors will be giving improper readings which can hurt performance and mileage. I have done both on other cars but i would not recommend doing this on your Lexus LS! The LS is not your Ricer tuner car or your old Chevy pickup.

diamondave I understand and appreciate your opinions, and yes the erg will gave you better mpg, but at the same time it puts in dirty hot air in to the engine. and I hate to tell you the ls400 is not the greatest car ever made, and the 3000gt vr4 with its 100hp per liter, all wheel drive, all wheel steering, electronic control suspension, active aero ,electronic controlled exhaust, cf 32) was import car of the year in 1991 the ls never won such thing. so yes its a vary good car but at the end of the day its a car, its a air pump and there many great cars. so lets agree to disagree.