Rep Power: 0

I have a 2012 civic sedan with a 1.8 L Automatic....long story so I will condense. thought I blew the head gasket after oil in the coolant turned my coolant into whipped cream. Prior to this the car was stumbling and missing at low RPM. Basically if I set the cruise to about 28 when the car drops into high gear it shakes but not all the time. So I will jump forward to the head gasket. during my investigation I learned the transmission warmer was my culprit....I found a low mileage (car has 200K new engine has 22K) and replaced the engine....only thing that was remaining was catalytic converter, reused my throttle body and did put my old fuel injectors on because one of the new engines injector was faulty. put car together....wash the transmission out and hit the road....all works but yes...the stumble remains.....I swapped the EGR from old engine...bought new forward and rear O2s.....no change.....put a new/used throttle body....no changes..swapped it again to ensure the replacement part was not damaged. No change....just swapped the MAF....no change...and oh yes....no codes are being thrown...Any ideas as to what else it could be? My mileage is also 5-10% off too....thank you in advance....
B

 
Rep Power: 228

Either fuel mix or transmission related, if there are no CELs, imo.

You could download the Torque app, and buy a obdii connector for your phone, to monitor fuel trims at 1500rpm. After that I'd take it to honda for a deep scan, probably not that expensive.

 
Rep Power: 0

I am now certain it is the trans....is pulling an automatic for a 9th gen sedan the same as the 8th gen?

 
Rep Power: 0

What should the fuel trim setting be at 1500rpm's?