Hey guys I know I'm new to these forums and I hate to just ask for help off the bat, but I've been doing research about my 2002 lexus gs300 and I am just stuck. When I first bought the car it had a problem with rough idling ( Struggling to take off, I had to kinda push the pedal down a few times in quick succession in order for the car to go) and I decided to do a tuneup ( sparkplugs, ignition coils, wires, air filters, clean throttle body,), and it fixed it for a while until about two weeks later, the car got worse than what it was in the first place. All my problems have to do with the car being at idle. Sometimes when I start my car, it shakes bad and the rpm slowly goes down until the car shuts off, I would have to crank it fast and put it into drive instantly in order for it to not do that. Another problem is when I stop at a red light or stop sign, it will shake, but wont shut off( I think because I'm pushing the pedal down) but it just hesitates to take off and it continues like that until luckily the car takes off( which is random) or I turn off the engine and take off as soon as i turn the engine back on. These are the only problems I know so far and I've been looking online and trying to figure it out myself the past month. I also checked the codes and these were the codes but my uncle is not convinced these are the problems.

P0175 ( Rich)
P0172 (Rich)
P0300

 

OIL CONTROL VALVE your welcome : )

 

I did some research and checked the oil control valve, but I cant seem to find the filter? I tried to look and see if it was stuck inside the hole, but I don't think i seen it?

 

Sorry had to do it. There are some pretty good threads on the oil control valve. <br/>https://www.clublexus.com/forums/performance/401898-p1349-vvt-system-malfunction-bank-1b-blocked-oil-control-valve-filter.html

 

Np ahah, I got it out with a hanger, and I cleaned it and it drives pretty smooth now. And i checked the cam shaft position sensor and it works fine. So i think I fixed my problem for now haha. Thanks alot man!

 

Did all those codes go away?

 

Thumbs up!!!!

 

I disconnected the battery while messing with it and so far no CEL or VSC so for now yes! Thanks alot btw.

 

Actually a new problem just arose now.... this happens 7/10 times when I stop and try to accelerate the car will just lag and catch itself or I will have to snap throttle it and it will instantly go back to normal. Do you know what the cause of that could be? I'm getting the codes tomorrow if that helps any. Also, when I'm just sitting in park the rpm fluctuates between 100-700 rpm and will just steadily go between that. It's at 192xxx miles also if that helps any.
EDIT: I also forgot to add that sometimes whenever its in that lagging state, right before it starts to accelerate i can hear a pop. from under the hood.

 

Anytime I disconnect my battery it takes a few trips of driving for everything to get back to normal. After resetting the computer it needs to readjust.

 

Aite, ill wait till the end of this week to see wussup with it. Thanks for all your help so far man!
It's my first car and im just trying to fix it all up before i head up to college.

 

Well, I dunno I've been riding around and it does this wierd thing when i push the pedal. The RPM just goes up while the car stays at 0 and by the time rpm hits around 3000 the car starts to pick up finally if that gives you any hints to whats wrong.

 

I know you mentioned that you did a tuneup but i have to ask this, did you replace any ignition coils are messed with your timing belt? I had the same problem with mine so I had looked into replacing 2 of the 3 ignition coil wire pigtail connectors.

It got rid of my CEL(random misfire) at startups but the drive ability issues were still there when I accelerated, car lost power and would surge tremendously. After doing the timing belt about a dozen times(thinking i was off a tooth), i finally messed up and had to get my cylinder head rebuilt due to some bent valves. I gave up and sold the car after 2 weeks of looking it over and ran out of ideas diagnosing it.

To make a long story longer :P. I kept in touch with the buyer, he said he fixed it after a few times pulling every part that was involved with the timing belt. He noticed that a tooth was broken on the Crankshaft sprocket. Missing a tooth on that sprocket caused the timing to be off and it caused the misfire and lack of power.

You probably wont have the same fix if you didnt touch your timing belt but I thought I share what I went threw.

 

I gave up too, I ended up giving it to the dealership in hopes of it being in a settlement and right now they are diagnosing it for $114, unless its under warranty which it would be free I'm hoping, but thanks a lot anyways. And I mean we did change the timing belt, but the only time it has a problem is when it stops and go, so i dont think it would be related to that.

 

Hey Nguyen, Sounds like we used to have the same problem. I got my 2001 lexus gs300 fix by changing my MAF ( mass air flow )
Let me know how that goes if you still have the car.