i'm helping tune a car that just got a 383.
it wasnt running worth a crap so i scanned it with datamaster and it was throwing a high map code
code 33
the map sensor is around 60 kpa at idle. my car is around the same and doesnt throw a code. but his idle is really ruff

i also notice the left o2 wasnt really moving at all. so i had a look at it and the wire was burnt on it... got a new o2 and the car seem to run great after that... gave the car back to the owner and ran good for awhile and it started missing. scanned it again and the left o2 wasnt jumping around at all, just stayed right at 400-500 mv. and once the computer went to closed loop i could watch the blm just count down from 128 to around 98 then jump back into open loop. swapped out the o2 again and it stopped doing that but it still running bad.

everything looks fine on the car. no vacume leaks that i can see.
fuel pressure is good.
any idea?

 

the opti is new also.

 

map sensor may be bad. get a new one from your dealer. aftermarket ones are no good. i have one and the plug is always getting loose, throwing a code. Check the IAC count as well

 

the map sensor is reading fine... i think its just throwing that code becuase its missing so bad at idle its not creating any vacume. i guess i could pull the one off my car to see if it help.


i did look at the iac count and it was only around 64