We have just had the same error codes and have changed both sensors, but that didn't solve the problem. We found that the wiring loom which connects these sensors was at fault, it was quite an inexpensive loom.

jskaggs 6 @ wind stream. Net

There is one relay in the relay box next to the battery that you may want to check is the EGI 1 relay....see if this is having an issue...it feeds power to the sensors.....

I believe it would at least start even of ther was one or two plugs/coils that were having issues....i have tested these engines by unplugging coils one at a time till the truck was running on just one cylinder....if you can post a email in your profile or here like this....name at suchandsuch dot com...that way wont get stripped out by the server i can send you some info on code E27/28......

Yes I bought this truck brand new in 06. Use it only a few minutes a day & only during spring & summer. I had a cat dealer install the last two sensors & it's acting the same way as it did before. It was running fine then engine started running like an engine with a big cam. Then lights came on dash & started flashing. Then wouldn't start back up. It did act like it was out of time when I first tried to start it. What should I try first? Would it not start if it was coil or spark plugs?

Code E28:

At start-up, no camshaft position sensor (PHASE) signal has been detected for more than a predetermined period.
*The camshaft position sensor (PHASE) signal is not detected for a predetermined time during engine running (during crankshaft position sensor (POS) signal input).
*The camshaft position sensor (PHASE) signal irregular waveform is not detected for a predetermined time during engine running (during crankshaft position sensor (POS) signal input).


You say the truck is an 06 bit only 300 hrs??...you owned this truck the whole time or purchased second hand?...find it hard to believe...

As for my own experiences...did you use original equipment when replacing what you replaced??...these engine dont do well with aftermarket cam or crank sensors...i would suggest replacing BOTH with OEM sensors...
Another problem i have found is that the spark plugs are wore out and the gap is to wide causing a misfire issue that is detected by the sensors and throwing a sensor code when in fact its the spark plugs...can also be a coil pack causing the same issue...i would also recommend changing all spark plugs and any coils that may be defective....WITH OEM PARTS....youll be farther ahead in the long run...non oem parts cause more headaches than they fix in these engines...