Please help my 2001 gs300 has been running sluggish for week and especially when I floor gas pedal, and today on the freeway it would not go past 60 MPH,Then suddenly it decreased to 50,40,30 MPH then I was going 10 MPH on freeway and I had to pull over,after another mile to car stopped.I had to get it towed,The car runs now but barely to about 20 MPH and the check engine light has been on for a year but I was told not to worry its just the O2 sensors,I had it ran for codes 2 days prior to this that happened today with the car shutting down and the code was PO 420,I don't know if I need a new 02 sensor or a cat converter,please help,Thank you your time is appreciated.

 

welcome. moved to right forum. good luck.

 

Try googling that P code or do a search on here, and please, don't wait an entire year to verify a check engine light.. one overlooked problem becomes a major overlooked problem.

 

A year!!! Oh my, I'm at the shop the next day with a cel, no good man..

 

Check engine light means check the engine.... lol.

http://www.obd-codes.com/p0420

 

its your cat! hopefully its only the cat and not your 02 as well