alright so i have about 5000 miles on the new 306, had alot of problems at first cause i was trying to make speed density work with a maf computer well i finally switched over to maf and it solved all my problems until the last month or so....not only is it cold blooded all of the sudden" well before the engine swap it was never cold blooded" but that is not my problem...when driving in any gear and just giving a little gas it has this bad sputter and will sometimes backfire at the intake when you throttle up.....but if you stay on the pedal she runs great...only codes that i get are typical e.g.r. not working, air system inoperative, and a mysterious 91...i even just tried disconnecting both 02 sensors and nothing changes

 

it seems that this used to only happen when it was cold but once warmed up would go away but now it just does it all the time

 

MJR46 please help...i am pretty good at diagnosing things on my car, thanks to the help of everyone on this site but i am stumped on this one....unless it is as simple as an 02 sensor, but would that cause the problem i am having???? now that i plugged my 02's back in and run a koer i only get code 92,33....92 being the driver side 02, i did replace one a while back but it appears it was the passenger one

 

my car dose the same thing and also gives me the 91 code. i would like no know whats going on also

 

timing is probably out

 

they will sputter, hesitate and backfire when an injector gets dirty. Could have got some water in the gas.

 

swap the suspect o2 to the other side and see if the code switches to that side, if so = bad 02, clear code then rerun koer to see if prob is corrected...LUK

 

i got a new o2 senser on the drivers side and car runs much better.