1997 Chevy Lumina running rough and dying when idling. Changed spark plug wires, spark plugs, fuel filter, and oxygen sensor. After completing tune up car ran rougher than before and gasoline flowed out of the exhaust pipe. Can you suggest how to correct?

How long since overall tune-up? Any applicable trouble codes?
The basics for a rough idle, check for a leak of some kind, fuel--egr--vacuum, something of that nature. Does it run ok off-idle?

Does the truck seem fine when you first start it & then acts up when it reaches operating temp?
That would lead me to look at my oxygen sensor, a bad sensor can cause the truck to run "rich" which would explain the fuel smell in the exhaust.

So many options...oxygen sensor, egr valve, pcv valve, premium gas.

When it stops running and will not start back up, you'll need to figure out if you are lacking spark or fuel pressure to proceed with testing.

Rough idle could be the throttle position sensor, or the idle air control valve.abs could be you need brakes or just the abs sensor is bad

Hi, Try to replace fuel filter. It maybe clogged up and making engine run rough or poor. Also check and replace spark plugs. A bad spark plug will make it run rough too. Good luck.

Oxygen sensor only report the condition of the engine the rough running condition can range from a worn sparkplug wires to worn sparkplugs to valve problems to injector problems. with the cadillac deville a tune up should be the first attempt to smooth the rough idle with the inspection of the cap and rotor cap and rotor do have a tendancy to arc internally and create misfire so does sparkplug wire that can leak spark voltage to ground and create misfire. the spark plug wire especially if they are brittle and hard can create issues

Check the DIS module or injectors. Check to make sure you have a spark on each cylinder. One cylinder could be misfiring

Unless your vehicle is really old and has a carburetor there shouldn't be an air mixture screw. Air and fuel mixture ratios on engines with Electronic Fuel Injection or EFI are controlled by the vehicle computer witch receives and sends information to and from a slew of different sensors like the oxygen sensors, throttle position sensor, the idle air control valve, Etc. Chances are you have EFI on your vehicle. If your engine is running rough or lacks power, try a complete tune up. New spark plugs/wires, new fuel filter, new air filter, oil and filter change, new oxygen sensors. Try running a bottle of injector cleaner and a bottle of water remover through the vehicle and see if it helps. Hope this helps.

it could be an o2 sensor. it could also just need a tune up