I am looking at getting a 2007 Lexus ES 350 3.5 V6 with 150k miles as a second car to drive long distances. I took it for a test drive and it wasn’t running right. It also has a check engine light. Despite this, The owner says it’s nothing to worry about. I hooked up the scanner and I get the code “P0303”. What does this code mean? Is it an easy fix, if I decide to buy the car?
Code P0303 means a misfire on cylinder 3. Swap coil packs. If the misfiring cylinder moves, get another OEM coil pack. If it doesn't move, see the FAQ, hyperlinked here. Engine Misfire – How-to – Ask Scotty Community (carkiller.com)
It is highly recommeded that you take this car to a skilled and experienced mechanic and have him give you a list of problems he finds and how much it would cost you to repair. A Toyota tech would be best if you could find one. It's especially important given the car's age and mileage. You will need to pay this mechanic for his time. He should have a sophisticated scan tool to go deep into the ES350s computer subsystems. Then you'll find out if the check engine light (CEL) is something to worry about.
If the seller is unwilling to let you do this, walk away or if you love the car, give some low ball offer and if he accepts, consider the purchase as is and all problems it has will be your responsibility. If the seller will let you take it to a mechanic for evaluation, you can take that problem list/price estimate sheet and negotiate the asking price. By the way, the seller might want your mechanic's report. If it were me, I wouldn't give it away.
Good luck whatever you decide...Dave, 2007 ES350 owner 267K miles
