A vaccume leak could cause that OR one of the hoses going 2 the gas evaperator canister OR a hose going 2 the Tank or filler neck.
The filler neck could be cracked at the tank
You may simply need the have the code reset. If, after being reset, the check engine light comes back on, then you have further problems.
Probably the filler neck is rusted through.I had the same problom on a 1996 Pontiac Grand AM.
Fixed the same on my Venture 2001 by changing the vacuam purge switch ...looks like a solenoid switch connected to and located near the vacuam canister ... easily remove.
Have vehicle scanned to determine the problem
It can be many things. Can be a blown head gasket, stuck thermostat, cooling fan not working properly, water pump problem, etc.
check the #18 fuse for the injector in the engine bay. My 2001 venture blows that fuse when the wipers are activated. Im in process of finding the problem.
VTEC may or may not work when the check engine light is on. It depends on why the check engine light is one. If it is on because of a problem with the VTEC system, then, no, it will not work properly.
Do you need to check two possibilites, one, check if the oil is from transmission or from the engine, if the oil is red,is from transmission and you need to replace radiator, if the oil if from the engine you got it a big problem, because the only way that the engine oil is inside the radiator is because the engine has a bad head gasket, that mean you need to repair the engine heads.
Have vehicle scanned to determine the problem and have codes cleared
It could be any number of problems. If you can hear the engine cranking but it doesn't start, you have a problem with either fuel delivery, ignition (spark) or compression. If you have all three functioning properly and the engine cranks, it will run. If you can't hear the starter turning the engine, it could be a bad connection, the starter, the neutral lockout switch or the keyswitch.
Because the engine is not properly configured
it can be of all stupid things a improperly fasstened gas tank cap
This could be a problem with the oil pump. Just because you have oil visible on the dipstick does not mean the oil is properly getting to the engine. Have the vehicle serviced as soon as possible to avoid engine damage.
The engine will run inefficiently.
Could be a fuel delivery problem such as a dirty fuel filter.