Have a 04 mazda 6, it will suddenly start sputtering and will not accelerate, till you shut off the engine and restart it, any ideas? I took out the gas tank, had a little water cleaned it out changed the o2 sensor but still the same problem, computer reads nothing???

 

Not enough info, background and why you removed tank (how did you suspect water---what was it doing?) or changed O2 sensor.

mileage, automatic or standard, # gears, fuel injection or carbureted if possible. EXAMPLE: 2006 Mazda 6 GT Wagon, 6 speed automatic, 50,000 km (or mi), fuel injected. Please make sure to list any mods such as aftermarket K&N cold air intake, headers. When making a post please make sure you also include any important services, like when you changed the spark plugs last, ign coils, coolant, transmission fluid, PCV valve.

 

04, 6 cylc dohc no modifications, pulled the gas tank because I had a camaro that did the same thing and water in the gas tank was the problem, common with cars in this area, tropics lots of humidity, rain tanks build up condensation,
o2 sensor was changed by the dealer, they had it 4 times and same problem keeps occurring. it has 55000 miles. it runs fine then starts sputtering, you shut it off turn it back on and the thing runs fine for a while then dose it again. its automatic with speed shift, when it happens all the lights come on the dash, hook up a computer and it shows nothing.

 

Ever try to re-set the computer? (disconnect negative terminal, press on brake pedal a few times, and leave it alone for 10 minutes, re-attach battery, let idle for 10 minutes).

Ever have a check engine light code?

Your coolant should also be changed, the coolant sensor does weird things if clogged.

If you are having condensation in your fuel tank you should never drive around with it below 1/4 tank (or maybe higher). This also is better for your fuel pump as the higher level helps cool your fuel pump and it will last longer. I hope you don't have fuel line cracks, leaks. Run some fuel system cleaner thru.

With a 2004 and that many miles, you are pretty close to a spark plug change. Mazda never changes or inspects the PCV valve so do your self a favor and change it. With it being a 6 cyl, the PCV hoses where not that good either (they collapse) so get a hose from a 2006, I have 2 PCV in line (not necessary). A good cleaning of the throttle body and MAF sensor usually help as well (while battery disconnected). Check for vaccuum leaks on the main intake tube as those accordian tubes do crack.

If and when you change your spark plugs, clean the egr valve and cut the egr tube back.

Spark Plug Change Read: https://www.mazdaforum.com/forum/maz...ocedure-29393/

EGR Tube Modification Read: DIY: EGR Modification/Optimization (3.0L V6) - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum

 

Another good cleaner which really helps the catalytic converters and O2 sensors is lacquer thinner (not paint thinner):


I have done this as well as Tanprotege who actually had a code and got rid of his code as well as better performance, driveability.