I kno there is tons of threads about these but i wanted to get some opinions on things to try before i replace the opti. I just changed the opti October 06' and it was an AC Delco opti i put back on. The car is a 1994 z28 (()It has a 96 model motor tho, with the Vented opti)))

Car will stumble multiple times upon tryin to crank, White smoke will barrell through the ram air when it backfires. Read the codes with a snap on scanner and it says, 36 High Resoulation Pulse failure, 42 EST grounded, and 33 Map sensor messin up.

I had a used map sensor off my old motor, changed it out, NO GOOD... the car HAS BRAND NEW NGK iridium spark plugs with taylor spiro pro 8mm wires!!

When i turn the car on, smog pump will go on and off and so does the motor fan, the rpm needle will jump to 3 grand and back..... IS there anything else i can trry before i start on the opti... any suggestions or opinions appreciated... Thanks guys