REDLINE36

Hello,
I am an avid Toyota owner and now I got my first Lexus, a 2008 IS250. I purchased the car not running as it had a dead fuel pump. I installed a new fuel pump and it fired right up and ran great. I reset the codes and drove it around for a bit and got a P0303, I cleared it put some injector cleaner in the tank. Drove it for a day and it popped back up. I did a bit or research and decided to swap 1&3 coils, gone but after a day it came back, swapped 1&3 spark plugs along with a compression check of the right bank (all 170-175 PSI) and a new air filter, same result. when the car runs it runs great also it has 203000 on the clock so I was really impressed with the compression check. Does anyone have any other ideas that I might try to solve this issue.

Thanks

2013FSport

iTrader: (2)

Its a good candidate for carbon build up in the intake. Do a search for intake cleaning and wallnut shell media blasting.
To confirm, you pull the upper intake off and look at intake valves. If you can't see them, its likely the problem. All DI engines suffer this fate.