The P0420 is most likely due to the engine's condition. Prior instances of the code were probably due to poor performance also.
Gas in the oil is generally bad rings. It will be coupled with lower compression. The gasoline dilutes the oil so you lose lubrication in the engine. Don't drive it with the oil/gas mix.
A lot of short driving is not good for any engine. You are experiencing high fuel consumption because the engine isn't warming up good. All cars need good long drives on occasion lasting 20-30 minutes.
Weigh your cost. What condition is the car in overall? What will it cost to rebuild? Replace? What would a replacement car cost you?
Car-Part.com--Used Auto Parts Market
JDM Engine Depot
Check with LKQ for availability of a used or rebuilt engine.
Gas in the oil is generally bad rings. It will be coupled with lower compression. The gasoline dilutes the oil so you lose lubrication in the engine. Don't drive it with the oil/gas mix.
A lot of short driving is not good for any engine. You are experiencing high fuel consumption because the engine isn't warming up good. All cars need good long drives on occasion lasting 20-30 minutes.
Weigh your cost. What condition is the car in overall? What will it cost to rebuild? Replace? What would a replacement car cost you?
Car-Part.com--Used Auto Parts Market
JDM Engine Depot
Check with LKQ for availability of a used or rebuilt engine.