Scag backfire and engine miss

I have a scag smt-61v turf tiger built in 2008. Last season i would mow for about thirty minutes and it would bog down, backfire and choke out. I would let it cool off and it would mow for about thirty minutes more before it started again. It is EFI water cooled 31 hp kholer. The codes it gives me is three flashes and then one and then six flashes and one.

I have changed the plugs purchased a new air filter and fuel filter. I also pulled the fuel,lines and cleaned the tank. I also replaced the oxygen sensor on the back because the code of three and one said it was the sensor. It still misses and backfires after doing all of the above maintenance. I can’t seem to find what code 6 and one
Pertains too.

When the engine starts acting up I got off and pulled the plug wire off the spark plug on both sides one at a time of course and the engine still ran. This indicates that the coils are firing.

Does anybody have any ideas. If I have to mow again this year in thirty minute increments I’m going to go crazy.

Any suggestions or help appreciated. What does code six flashes and then one flas mean? Where can I find it?

I do not know your engine model, but looking at the manual for the Kohler LH775 which I believe to be the same/similar, it shows that a code of 3161 is actually code 31 and 61 denotes the end of code transmission. Code 31 is "O2 Sensor Circuit: Shorted to Battery" with an additional note of "O2 Sensor Short to Battery diagnostic detection is disabled with SAS fuel-cutoff calibrated out."

I do not know what all of this means, but it could be something as simple as replacing the 02 sensor?

Hope this provides some help!

Thanks Mike that was the first thing I did was replace the O2 sensor. It didn’t fix the problem. I put an ohm meter on it and it’s not shorted to battery. I have a lean fuel situation going on somehow. I have cleaned and replaced all fuel lines and filters. I guess I’ll replace the fuel regulator and if that don’t work the fuel pump. My engine is the LH755S

STILL TRYING TO FIGURE IT OUT

Could be fuel pressure related but Kohler also mentions that is could be an exhaust leak, aka exhaust gasket or other muffler issues, Also a bad o2 sensor ground to engine which could also be related to exhaust gaskets and mounting to engine. Also could be a bad ecu to engine ground.