LS1 Trans Am wont start grrr

[ccckeeper]

Car seems to randomly misfire when its been raining and now wont start. Throwing codes P0351,P0353,P0356,P0357&P0358.
First time it cut out completely and over revved when starting as it suddenly cut in with throttle open. Then starter motor casting cracked and starter rode the flex plate. I have changed the starter and flex plate and engine started but sounded like a bag of nails. Two rocker bearings had collapsed. Changed Rockers to comp cams ones. Car ran great for a week or two now misfiring again with the codes shown above. Have checked all the coil connectors and all looks ok. Ive cleaned all the earth bolts and live feeds to the relay boxes. Car misfires badly and wont start. Does anyone have any advice, could it be crank sensor or CO2 sensor?
1998 LS1 Trans Am, Comp Cam rockers, K&N Air Filter, Borla Exhaust otherwise believed stock no other fault codes but guages go haywire when its misfiring, speedo goes fullscale low oil light comes on.
Anyone have any ideas?

[Davy J]

If gauges going haywire would that be an electrical fault ?
I'm not a mechanic just a suggestion. Ask Robin at Autopontiac.

[bhm1712]

Did you manage to sort this out Paul? Don't remember you saying anything at Wheels day - unless this was what we were talking about with the ECU being a bit exposed to water? (my memory is crap lol)