code 0951

[Neighbor]

2007 cm 870 engine code0951 pid 166 spn 166 3 inactive counts with no lamps, smokes and smells like a little bit of fuel. Did not see anything when doing the cylinder cut out test or balance test. did have this similar problem last year ended up replacing cylinder 1 and 5 injectors and metering and timing actuators, which now have about 175000miles on them, should i do a bubble test and check actuators again. Engine was rebuilt and Tun$ed by Mr Hag down in GA 2 yrs ago and follow all the recommendations from this site about maintance