Hi guys I've tried to search for this but all seem to differ fr my problem slightly :/
I've just done another engine swap I swapped out my b16a block for a b16a2 block and bolted all my parts onto the new block hooked everything up and plugged everything in car starts and idles at 2,500 cold then won't go below 2,000 when warmed up... Also when I'm driving along at low revs and put the accelerator down the car "chuggs" along as if its struggling to build up the revs and its actually like a violent struggle you get shoved back and forward in your seat! but then its like when it gets to around 4,700-5,000 it pulls strongly then when it engages in vtec it pulls as it should any ideas how I can solve this?? Code 10 (air) and code 20 (eld) are present but they were there with the old engine and this problem wasn't there

 

Bump!!??

 

can you post a video

 

I have seen this at cruise around 2800-3500 rpm if the o2 is on its way out, it can't meter the fuel and causes the stumble.

Just one of the reasons that this can happen.