My 94 Accord has just failed it's MOT on excess exhaust emissions. The car has been lying idle in my carpark for two years so I'm thinking this may have caused the smokey exhaust. It passed it's MOT before and has not been used since.......Any suggestions on how I might fix this problem? Someone suggested taking it for a long drive up the motorway to clean it out. Another suggested running it without the air filter for a while.

 

What are the emissions levels? High NOX is usually an EGR problem.

good luck