Im2nyc3

First of All I would Like to thank everyone who helps ahead of time. These forums are great.

I have a 2003 LS430 with 146K miles on it and just recently I'm noticing my car takes a little longer to get up to speed. I changed the oil and intake air filter. No effect. Transmission shifts fine and I changed the spark plugs about 50k miles ago. Someone recommended changing the fuel filter but no one seems to have a part number I don't have a lexus dealership for miles around here. The haynes manual that someone checked for me says it was in the gas tank. Was that correct. Either way I could use some advice.

ultm8mind

iTrader: (3)

I would add a bottle of fuel injection additive (or two) into a tank of fuel. May be your injectors, then again it may be your plugs too(even though you swapped them 50k ago). It honestly could be any number of things, catalytic converter, exaust leak, injectors, fuel filter, plugs, so many things...try the injector cleaner though.

Jabberwock

I agree try running a can of Techron Plus Concentrate fuel system cleaner, large size can.

Also pull the air filter box and intake hose and clean the TB and butterfly valve assembly with TB cleaner - they can really get gunked up with high miles.

Clean the MAF sensor - you can use electronics spray or CRC brand MAF cleaner but there is debate on it that is safe or not - I have used it 3-4 times with no ill effect. .

Could you have gotten hotter or colder plugs by mistake? Also definitely check all air hoses and vacuum lines around the TB and engine in general.

Im2nyc3

Thanks I added some lucas fuel treatment it only cleans the injectors. I'm on the second bottle now and I'm not really feeling a difference.

I'd like to replace my cat. A while ago I had my check engine light come on and I got the obd code saying the bank 2 cat failed. I ended up having to fix an exhaust leak that fixed the check engine light problem. I'd like to replace the cat anyone know where I could find direct fit cats other than from the dealer they run about $1200 ea and I wanted to go ahead and replace them both but at that price I may as well get a new car and use that for a down payment.

Im2nyc3

Thank You both and I'm not that much of a mech when it comes to cars

jimbosr1

i have always changed the plugs at 50k miles.i would change the plugs.its a cheap fix if you do it yourself or have a friend do it.

CarGuy89

When you say sluggish, do you mean a hesitation from the time you push the gas pedal to the time the car responds or are you more referring to the feel that the engine isn't pulling as strongly as it normally does?

Im2nyc3

Yes I was referring to the time. Once it gets going it usually picks up like normal. It could be a little of both but mostly the hesitation. Thanks I hope that helps

leemeedee

Question for those who have tried the injector cleaner. Do i use another bottle after i finish my full tank of gas ? i have a 08 IS250

honeygee2

try this stuff
http://www.seafoamsales.com/gasoline-engine-faqs.html

groomerz

i would reset the ecm back to defaults disconnect the battery for 5 min then reconnect. The car learns your driving habits and also retards the ign timing map if non premium fuel is used and knock sensors indicate detonation from low octane fuel.