My service engine soon light has been on for awhile and don't have any reasons for it to be. I hooked it up to a computer awhile back and they said that it was a carbon build up problem. They told just to run some cleaner through it and I did. The light stayed off for a week or two and now it is back on. I don't want to take it to a dealer and get screwed. So I was wondering if anyone had some suggestions. Thanks

It sounds like the e.g.r sensor is cloged or has gone bad.try running some more cleaner threw it.maybe hook it to the computer again,but most likely the e.g.r will need replaceing on some cars u can take them off yourself and clean them they have a screen in them that gets clog,let me know if this helps u

Start running Mobil 1 or Amsoil synthetic engine oil in your car. The NOACK volatility is much less on synthetics than on conventional oil. On conventional oil, the small, light molecules evaporate and are recurculated through the EGR and are burned. It can set up a vicious process where metallic oxides from the burned oil plate out on the spark plugs, interferring with combustion and causing carbon buildup. Synthetic molecules resist heat and evaporate much less. This results in a much cleaner engine. I have 122,000 miles on a 1993 Civic and have never had to even replace the PCV valve or its vacuum hose, because there has not been any sludge developing at all. However, I have only run synthetics in it since 1,100 miles. Also, add Shell Regane or Chevron Techron to your gas every 3,000 miles. Change your synthetic oil and filter every 6,000 miles or 6 months, whichever is less.