Just wanted to give my story on my experience on this subject. I had check engine light come on my truck several years back and my scan tool told me that it was my camshaft position sensor. I read up on it and it looked real tough to replace. The check engine light was intermittent but was definitely on much more then off. The engine ran fine though so I figured I would let it go. But my great state of communist California decided ,11 years after I bought my truck , to "smog" diesel engines. Another money grab in the name of mother earth! So I cleared the code drove it over to the smog station and my truck failed. Now I bought the part ,camshaft sensor, $60 bucks and got to replacing it. I tried removing my inside fender cover, that didn't help at all. getting the part out was tough but only took my about 20 minutes to do. Putting it in was another story . It is so tight in there between the vp44 and the engine block. it too me 2 hours getting the cp sensor screw in. I had to force my hands , yes both, to get it started. used 1/4 inch drive with small extension. Hands were bloodied and bruised. I had to remove the throttle sensor box to make room for my hands. It helped . So now the next day check engine light comes back on. Oh no. it was the throttle sensor this time. I looked into buying one, wow $150 or so. Read up on it on TDR and the fix was to undo my batteries for half hour trick with resetting the throttle sensor with the accelerator pedal. It worked. Yes no money spent. It passed the smog test, 50 bucks later. Thanks for the info on throttle position fix. This web site is so helpful.