about 2 weeks back, i converted to edelbrock elite valve covers, and got rid of the passenger side breather that goes into the throttle body..instead im using a push in breather filter...

right after, with no other changes, cold starts became slightly rough, it would idle hunt for a minute or two, then stable out, wasnt a big deal...

Now, a few sundays ago, i had a decent nitrous backfire through the intake manifold..

it blew the maf tubing and a bunch of vac lines loose, but otherwise, didnt hurt the motor at all.

the very next morning{after putting 100+ trouble free miles on the car AFTER the n20 backfire...} it had a very rough cold startup..

wouldnt idle, seemed to have a dead spot when giving it throttle, and it would pop/backfire slightly through the intake when you tried to give it throttle..when its done it, ive either just started driving right away to warm it up, or held the rpms at 1500 or so for a minute or two, and then it seems fine...

after 5 minutes of driving or so, it runs as if nothing was wrong,doesnt seem to have a lack of power AFTER it warms up, but when its cold, it deff doesnt pull like it used to/should unless i go WOT.{yes i know its bad to go wot on a cold motor, dont need that lesson plan...ive done it for diagnostic purposes only}

last night while driving home, car flipped a SES light while cruising 70mph on the freeway,didnt run any different at all, got home and pulled the code, its a code 44...

Also, for the sake of argument, this car HAS seen leaded fuel{for nitrous purposes} but id imagine its only seen maybe 10/12 gallons of 112 leaded...