any other way to lower a slightly high idle

[bonestock240sx]

back in november i got a 91 240sx and i decided to spray some power foam through the intake and i messed up my car instantly. it took about two months to figure out the problem. it ended up being the TPS. in the process we cleaned out the iacv replaced o2 sensors swithced out maf's and all that jazz. well i got my idle down from 2200 to 1000 which is freaking awesome compared to what it was. before i swapped the tps the only way i could get the idle down was to retard the timing and screw in the 2 iacv screws all the way. after i replaced the TPS i was able to put it back at 20BTDC (stock) and instantly the car was back to new....kinda my idle is still at 1000 i can't get it any lower. any other suggestions. im trying to get everything back to proper working order. i know its only abour 250 rpms but still if you have any suggestions let me know. and yes i searched days and days when i messed my car up in the first place so i dont need to hear search. unless there is something i missed which is highly unlikely.

[grecco28]

i recomend check for air leaks on intake manifold gaskets (2) and vacum lines, maybe the foam cause an old vacum line to collapse or blew a intake manifold gasket...