SUSDAVID

Hello all,

I have a 2002 Lexus GS300 that hesitates to accelerate when I am at a complete stop. The car kind of jerks or kicks back trying to pick up speed. The RPMs also drop almost to zero when I am coming to a stop or making a turn and the steering wheel stiffens up.

Check engine light comes on and off sometimes and it has flashed at me a couple times before going solid. I took it to a mechanic and gave me a list of codes that were given as seen in the first picture. The main work to be done is replacing the timing belt and new spark plugs ( I just had the spark plugs replaced back in January)

I took the vehicle to two other mechanics and both told me that it is the o2 sensor and damaged catalytic converter. I am more inclined into believing the two other mechanics as they both gave me same diagnosis.

I also have VSC, VSC OFF, and ABS light on. I think that the ABS may have something to do with the sensor that I replaced with an autozone sensor?

My wheel arm broke when I was on the freeway near the carpool lane so I dragged the car across the freeway and into the shoulder ( probably not the best idea) and had the sensor replaced with auto zone part, light has been on since then.

I have no clue what can be causing the VSC lights to come on but the codes are on the first image as given to me by the first mechanic. I had another mechanic tell me this may be caused because I have not aligned the car.

I would also like to point out that a smell of gas comes and goes randomly at times.

I have cleaned the MAF sensor, throttle body and air box and all seem to be good.

any help would be greatly appreciated as I do not want to spend money on something that isn’t going to solve my problems!!



First mechanic I took the car to gave me these codes. Below is the scope of work he proposed for $650. Timing belt, check for leaks and valve cover gasket.

I took the vehicle to 2 other mechanics and both told me codes that were given were for o2 sensor and catalytic converter.

TrueGS300

I'll do my best to explain whats happening based off your codes and description of symptoms. First know that when the engine light is on, it will light up the VSC and ABS lights too. That's just what Toyota does to get the driver to take the car in. I do believe you have ABS issues and will need some work in that system. However more importantly, you engine runability issues are top priority.

First, you may need a timing belt and plugs. But I do not think they are your issue. You have no codes that would lead me to believe timing is off. If the belt is cracked up, ya it should be done. If the plugs are beat, ye they should be too and they may be causing some misfires. But for the sake of getting it running right here's what I'd do.

First: The lean codes are top priority. If you are leaning out (or running out of fuel), you will certainly have misfires. I believe the misfire codes are a product of the lean running condition. This also makes searching for a fuel leak paramount as you stated you smell fuel and the car has lean codes. I suspect the leak would be in the fuel feed line somewhere if a leak does in fact exist. A leak at the tank or filler neck wouldn't have to do with the pumps ability to keep up pressure. So look for leaks while running along the fuel line and rail.

Second: If there is not a fuel leak you need to find whats leaning you out. Start by inspecting the intake. Open your air box, make sure a rodent hasn't filled it with a next (had this happen this weak at my shop). Make sure the air filter is in tact and clean. Makes sure there are no holes or missing connections or hoses in the intake tube going to the throttle. If this is all in good order. Clean you MAF and Throttle body. Your low idle and hesitation seems like a gummed up throttle to me. And this will cause lean issues and misfiring if bad enough. The do a re-learn of the computer with the battery disconnect and cable touch method.

Now about the o2 and cat codes. These are not at all worth going after until the engine is running right. Misfires are what kill cats quick and you have mad misfires. I have cars come in with misfires and cat codes all the time and we always start with fixing the misfires and clearing codes and rechecking because the cat codes don't usually come back. I'm not saying your cats are good. It may be too late for them. But you must get rid of your misfires and bad runability before chasing that issue. It depends how long and how bad they have been abused by a poor running engine.

There are so many factors here that I can't know. You may even have destroyed or plugged cats at this point that are a blockage of exhaust flow. I'm just saying, you have to start with why the thing is leaning out.

SUSDAVID

Thank you for the response. I forgot to mention that I did clean out the throttle body and MAF sensor with the appropriate cleaners. I also dismounted the air box and cleaned it out. Air filter is fairly new as well. I will check the lines for the fuel leak and clean out MAF sensor and throttle body again.

I do believe that the cat is too far gone as I have been driving around with this issue for a long time and use it as my daily driver. I will let you know what I find.

kevin3344

As mentioned you'll want to go through everything, MAF (clean or replace), air box and throttle body. Sometimes it's not enough just to clean it. Make sure everything on the throttle is working correctly. Grab a multimeter and go through each of the steps below.

How many miles on the vehicle?

daddyblack

check your vacum sensor switch hoses the switch is underneath the pcv valve green plug it has a u shaped hose that is probably dry rot just had same problem and that what it was got switch and 2 hose set from dealer for under 200 dollars