aj01gs300

Just purchased for son a 2001 GS checked out by garage. Said great car. 1 and 1/2 month later started with misfire p303. and VSC lights on
Took to garage who recommended all plugs, wires, fuel injector clean. Close to 1,000 dollar price, Declined total repair(finances not available) and they replaced #3 plug and coil. ran great again for a day now 303 error and gave one 300 error.
Then cleared errors and back to 303 only. From reading post I should start by changing plugs, which I will try myself, any other ideas or comments before I get into it.
Other info: happened during extremely cold snowy weather 0 to -5 I believe he also ran 89 octane, I added premium gas, injector cleaner and gas line antifreeze.
Thanks for any help!

ps I am not sure how you determine the generation of this car

Gotcha350

You have a 2nd Gen car...the 3rd Gen 300 is a completely different engine...start by replacing the plugs like they said...

Also...if you are going to run anything through the fuel system I recommend Techron complete...

Good luck!

aj01gs300

I appreciate it!

SILENTM

If they already replaced the plug and coil already i would look into getting a compression check, then maybe switching injectors to see if the problem followers the injector

aj01gs300

After reviewing the posts on this forum, I thought I would find a reputable specialist to fix this car. I was glad I did. We took to an Independent Repair shop who only work on Toyota, Lexus, Scion and was glad we did. If you are in the Lexington KY area Lowell's Independent Automotive, Inc is the place to go. They pulled the car in, diagnosed and an hour later was out the door with a great running car again. I only wish I would have went there first, as it would probably have saved us about $500! They replaced the plug wires and it's running like new again, considering the same error code probably all that was wrong with it the first time. Around $250 and all is well again!