Code 0027 a week after Timing Belt Change

[jsimons944]

Background
Last weekend, I finished changing the timing belt [2006 XC70] using the IPD tool that clamps the cams on the rear [drivers side].
After fitting the new timing belt, rotating the engine 2 turns and starting the car, all was OK.
I put it all together and drove 2.5 hours on the interstate Monday, an hour to work Tuesday- Friday, then 2.5 hours back home on Friday night.
All seemed good; performance was normal.

Problem
About the time I finished that last trip, the Check Engine light came on, and the P0027 code was indicated.
This apparently indicates a problem with the exhaust timing.
I have not opened the covers to check the cam and crankshaft marks.

I suppose I can't avoid opening the covers, but what is the next step if the marks are still in position?
How could I have driven the car 8 hours or so, without getting the code?
Unfortunately, I really can't ignore the code with black duct tape, as the Check Engine light will just continue its ominous warning.

Thanks,

Jim

[JRL]

You can.
It's the number of start cycles that trip the code, it's 1 tooth off

[jsimons944]

After 5 weeks, no further fault codes.
I'll post another note, if the code ever returns.

Jim