1999 Isuzu Vehicross 3.5L V6 Timing Belt 100,000 miles

I installed a new timing belt on my 99 Isuzu Vehicross and after about 3-4 minutes of idling the Check engine light came on. I had all three timing marks aligned. Could one be 360° off? Has anybody have any experience with replacing a timing belt on this engine?
I spoke to the nearest dealer, service manager, Boy they where no big help. They couldn't or wouldn't answer my questions concern the CKP sensor on how many notches the sensor is looking at on the crank nor the timing marks and shaft rotation. I guess they can not do anything with out a computor or something telling them whats wrong. If there is only one notch than I do not see any reason why the crank could be 360°. It should not matter Since it rotates 2-1 to the cams. The cams would only stop near the timing marks at one place after 2 or three revolutions. I think this is do to the spring load of the valves. Best I can deduct is that I need to be on the compress ion stroke on cyl. 2 and the exhuast stroke of 5. I guess I could remove all spark plug, put the spark plugs in on 2 which I did and felt compression when turning the crank. I guess I need to remove the plug from 2 and put one in 5 and turn the crank 360° and see if the valves are closed over 5. There is the possibility the timing is correct but something else is giving me the fault, but the engine seems to have no power under load and the exhuast smells of raw gas. I am wondering if the new belt is changing the timing a 1° or 2° since it is new and not worn or stretched and it is not correcting itself for this. I would hate to drive it vary far to have codes checked and damage the engine. HELP any body?