vr running rough, shaking and misfiring losing power

[3.8 mang mang]

Yo dudes, so the other day I was cleaning my car checking oil etc as a potential buyer was coming to have a look at it. Anyway was running fine before then when I started it to move it out the garage all hell broke loose and it just started shaking and misfiring on idle. So I drove it down the street and it would not go past 2 and a half grand unless I gunned it and was shaking pretty violently. Anyways I left it for a day and went to dive it again the next day and it has impoved a bit but still runs like a POS, loses power, shakes and misfires. Any ideas? I changed the fuel filter this morning but did nothin.

 

[two-bit]

check plugs, do an error check to see if any sensors are playing up, did you wash the engine bay at all?

 

[3.8 mang mang]

yes ive recentley done plugs and leads, and no i dident wash the engine bay but ill will check the error codes soon.

 

[3.8 mang mang]

checked the error codes got no. 31 theft deterrant signal missing so just going to replace the BCM and see what happens.