Andysavage

started my car up and check engine light came on for cylinder 3 misfire, code P0303. checked wiring, nothing torn or out of place, plugs good. Switched coil plug around to see if i would get another cylinder to misfire, no luck. took spark plugs out, they were dirty, looked like burnt oil maybe, just black residue. cleaned them with a towel, nothing crazy, ran ok for a bit, then after giving it gas over a period of a couple minutes, the car started to idle rough, sounding like it was misfiring, however no check engine light. my next step is to dry compression test. please let me know what i should look for. This is my first Lexus, more familiar with honda/acura, bmw. i read around about a recall due to carbon deposit? not sure if it has anything to do with it. Car has 118k miles 2007.

MikeyK02

iTrader: (7)

trippy

iTrader: (1)

did the car get the recall done for the carbon build up ?

pretty much carbon build the f up....happen to me goodluck

Innergflow

I recently bought a 2012 250, are those not affected by this or why is it not on that manifest. looks like it says 2006-2010 only.

minato

iTrader: (1)

Did you just get your engine bay washed recently? you have a 2012 model, so carbon buildup, shouldnt be happening to your car, I would get the car checked at lexus or an independednt mechanic. when you moved the plugs and coilpack around, you still had same cylinder 3 misfire?

noblesenga

MatthewMM

This is a known issue and Lexus changed the engine design in 2013 to have have manifold injection when the car is cold.

"December 8, 2015 MANUFACTURER COMMUNICATION NUMBER: L-TT-0192-15
Components: ENGINE AND ENGINE COOLINGNHTSA ID Number: 10152274

Manufacturer Communication Number: L-TT-0192-15

Summary: TT: Some IS250 and GS300 vehicles may exhibit one or more of the following conditions:

? MIL ?ON? DTC P0300, P0301, P0302, P0303, P0304, P0305, and/or P0306.
? 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.
NOTE: The recommendations in this document apply to an intermittent misfire concern. If a vehicle exhibits a steady misfire, the root cause is not related to the referenced service bulletins and the repair manual should be referenced for diagnosis."
https://www.nhtsa.gov/vehicle/2006/L...Communications
https://static.nhtsa.gov/odi/tsbs/20...52274-9999.pdf

My symptoms are also I get MIL, and VSC disabled lights. I used "OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows" (available on amazon) to pull codes and data logs: RPM, location Coolant temp...

I also forwarded the case to https://www.krinsklaw.com/contact and https://mccunewright.com/contact-us/ who have had class actions against Lexus and Toyota.

mr2turbo81

Hi guys... I'm having a same issue. Misfire on #3 cylinder P0303. swap coil around still get the same code P0303. I replaced the spark plugs with OEM ngk plugs and replace all coils since the car has 250k miles. the plug that came out of #3 cylinder had some oil residues on it... still the code came right back after clearing it. I check the wires for resistance from the coil plug to ECU... it came out fine. I even swap out a used ECU to see if it change anything.. still no luck. I did a compress test and they came out very good #1-200 , #2-200, #3-210, 4#-200, 5#-200, 6#-205. I even did walnut blasting on it to get rid of all the carbon build up. I then swap out all the fuel injectors with a remanufacture one from Denso.. still the same. I didn't check the resistance for the injector pugs to the injector module which I regret.. It is very difficult to get to those injectors. car seems to run a little better after new injectors. I'm running out of ideas.. all the wires looks fine, doesn't look like any rats got to it. My next step is driver injector module... I did lots of research but so far no luck.. Any help will be greatly appreciated..

thanks guys

MikeFig82

iTrader: (13)

Here's a good read. At first I thought maybe some type of arcing on that cylinder. Though you already swapped coils. So possible of other source affecting that particular coil.

https://easyautodiagnostics.com/misc...p-coil-tests-1

shadyfISF

Hi,

Did you find the source of the problem?