01 silhouette

the other day my wife went over the railroad tracks and the check engine light starting flashing....but ran fine. yesterday it started haveing a rough idle and low speeds, took it to local auto parts store and read code (p0303) misfire on cly 3. cleared code and restarted. light still flashing but no new code. question is where to start looking? plugs and wires (for problem with spark), fuel pump (as the fuel gauge had been reading diferent), vapor cannister (as i had a strong gas smell around the van yeserday)?

Well, sounds like you have several problems.....

Flashing CE light means you have a misfire that is bad enought to possibly damage the catalytic converter.....last complete tuneup(plugs, wires, fuel and air filter)? Check coil output with a spark tester.....

Fuel smell means you have a fuel leak.......could be a rusted fuel line, rusted fuel tank, leaking fuel rail, etc. ........should be taken care of right away....

Your fuel gage being erratic is another problem.....two possibilities....could be the fuel sender, or could be the wire harness connections that pass through the underside of the vehicle(approx where the rear of the driver's seat would be)....

i have only had the van for a about an year....so i dont know when the last full service (plugs) was. I had it on the lift last weekend to change fluid so i checked the pass-thu connector and fuel lines....everything looked alright. so i am leaning toward replacing plugs and wires first.....thanks