I have a fast 90/90 setup so I decided to go ahead and get a SLP 85mm MAF now my engine light came on..I havent scaned it yet so I dont know for sure if thats what caulsing it or not..it seems to run ok..I was just wonding if I need to have the tune adjusted for it?

 

yes you do.

 

Please give us a clearer picture of your setup. Has it ever been tuned before?I take it you have a 99 fbody w/ a 90/90 setup but no idea of what else. It needs to be scanned first then evaluated. With that said, without knowing anything else about your setup I would highly recomend that you ditch the SLP MAF and sub it with a 85mm Truck MAF. Same thing without the added SLP resistor.

 

the maf doesnt have a resistor...