Vehicle: 2006 GS300 AWD
Mileage: 145,000 km

I went on a trip for 16 days and the car was left untouched. Before leaving I got a fresh oil change and replaced the battery (had trouble starting it a few times in the cold so i got the guy to do a cca/load test and he told me it needed to be replaced).

Get back from my trip, start the car, and it has a rough idle, check engine light, check vsc display message and also this ( ! ). Turn the car off and on again, idles a little better but I notice when im driving the car seems to be louder then normal and drives a bit rough...

Dont think its the gas cap....

Anyone have some ideas? o2?

When I bought my car it came with the extra care protection package, wondering how much help that will be for this issue.

 

rough how?

did you change the battery? if so it could be the ecu got reset. Need to do a 2 weeks relearn thing over again.

 

Yes the battery was replaced with Interstate MTP-24

What is this "2 week relearn" thing you speak of?

I drove the car today about 100 kms, no changes. car seems to be louder then normal especially at lower rpm's

 

Sounds like carbon build up! You should have received a letter from lexus stating they will take your car and basically rebuild your engine

 

Need to do a 2 weeks relearn thing over again.

 

So took my car in to get scanned today....

Problem 1 - exhaust leak, my guy said hes seen this problem before in the exact same spot and was unsuccessful in welding.

Problem 2 - engine misfire codes, P0300 P0303 P0305.

 

Take it to the dealer! Theres a free extended warranty and I believe your car is in it.

Dear GS 300 Owner:
At Lexus, we are dedicated to providing vehicles of outstanding quality and value. As part of our continual efforts to meet your product expectations, Lexus would like to advise you of a Customer Support Program (CSP) which includesyour vehicle.
Lexus cares about our customers under certain driving conditions 2006 model year GS 300 and 2006 to certain 2010 model year IS 250 and IS 250C vehicles may exhibit an intermittent rough idle and/or illumination of the Malfunction Indicator Lamp (Check Engine
Lamp). The driver may notice this during the following conditions .
• Intermittently runs rough after coming to a stop with the engine at operating temperature .
• Intermittently runs rough with engine misfires present after a cold soak startup.
If this condition occurs one or more of the Diagnostic Trouble Codes' (DTC's) P0300, P0301, P0302, P0303, P0304,
P0305, and/or P0306 may be recorded.
'The check engine light may illuminate for reasons unrelated to this condition.
Although the engine is covered by the Lexus Powertrain Warranty for 6 Years or 70,000 miles (whichever comes first),
we at Lexus care about your overall ownership experience. To assure you that we stand behind our product, we are
offering this CSP for this specific condition.

 

Read this link!

https://www.clublexus.com/forums/gs-...e-misfire.html

 

Im located in Canada and already called Lexus....
Currently there is no TSIB/Recall for this up here.

 

Drive the car to the states, worst case. Here they have done plenty of the IS250's which have the same problem.

 

I reset the codes and they have not come back............. yet.

Now the big decision to replace the exhaust pipe that cost $1300 or not.........

Anyone have a stock exhaust laying around? I dont know if it makes a difference for part # but i have AWD model.

 

Come down to buffalo Northtown lexus if you have to. Call first and see if the recall can apply to you. Its only a 2 hour drive and they are a great dealership. My car has 200k and 12 years old and i still bring it there because I'm willing to pay extra for the service.

 

Take it to a muffler shop and see what they can do.

More likely the code will come back, you can try a top engine clean, where a mechanic sprays solutions into the intake.

Also is best to drive the car hard every once in awhile, to help blow out the carbon buildup.

 

The thing is my car has NEVER had misfire or rough idle problems in the past....
It only happined the first time I started the car when i got back from my trip.

Car runs perfectly, just alot louder then usual, especially at low rpm.

Keeping my fingers crossed that some muffler shop can hack patch this up, because im really not looking forward to forking out $1300 on oem exhaust + labour....

 

Had the same problem with my cat n took it to the Lexus dealer with the letter they sent me n got my engine redone completely at no cost!! (2006 gs300 RWD) it will be worth to drive to the states to get ur car fix..