Ok recently my 2004 honda civic lx coupe 1.7L D17A1 broke down on my way home. While driving home I experienced hard shifting and the car had almost stalled numerous times when stopped. I was on my final stretch home and attempted to use the highway while accelerating I noticed while I reached a higher speed the car would shake so I slowed down and took it easy the car then proceeded to hard shift down and only let me drive at max 40 mph then hard shift down again and boom nothing, battery still completely alive car would rotate but not start. Some history on the vehicle. I purchased this vehicle last year in november from a dealership and within the last 2 months did tune up (spark plugs, oil, air filter, oil filter) had no issues at all and car was running better than before AC was blowing stronger than ever and car felt amazing to drive. Since my car has broken down I've checked the following: starter, battery, battery connections, ignition coil fuse, fuel pump fuse. Removed coil on 4th piston and replaced because I noticed a crack in the housing of the coil. Still no good. When I removed the old coil I noticed a very strong gas smell and assumed engine was flooded. Compressed gas petal to floor and attempted to crank the engine with no success. Tried this a dozen times and nothing. While giving starter time to cool in between attempts. Can visually see belts spinning and can hear engine trying to turn over but nothing. Was told it could be crank shaft sensor but no codes detected. Only code that displays is in reference to O2 sensor not functioning properly. Fresh out of ideas and not to sure where to go from here. I do not know when the timing was last done on this vehicle.

 

Check the timing being off or yikes a broken timing belt.