check engine light

have a 99san with the python motor i have check engine light on all the time is there a diagnostic mode that can tell me some code or somthing so that i can sort it out
the motor has been converted to lpg so all the fuel injecton stuff is missing so the fault is not with that the motor still runs good i have been told that with check engine light on it goes into safe mode but this operates through fuel injection so this whould explain why it still runs good also it doesnt warm up and i have put a new thermostat in
its awsome other than that so any help epreciated

thanks for that i will try it and see let you know

i havent checked the oil senders yet so will do all at same time where are temp senders located?
is the sensor on the passanger side of the block (remember i have a v drive) not the knock sensor? just somthing i have thought about
will unpluging the faulty sensor make the light go out? i would have thought it whould need some kind of signal

The temp senders are both on the top of the intake manifold near the thermostat housing. Both oil pressure senders are located near the oil filter. One sender (switch) simply tees off the pipe to the main sender.

The CEL switch (senders) probably work by completing a circuit to ground. So, by disconnecting the wire to the switch (sender) the light should go out.

Had the same problem with my 99 Ski Nautique with the GT-40, only it got to the point where the engine started cutting out. Apparently, the switch was triggering the pro-tec system and shutting down as if we lost oil pressure. Quite a headache for a good part of the season, what a relief once it was fixed.