error code p1857
 

hello all, this 98 a6 had some overheating ussues so replaced all the bs including timing belt, water pump rollers ,,etc..... a few times before i did the work it misired and would barley move and then it would run fine. did all the work and it's doing the same thing but will not run correctly at all. misfires , won't idle and won't go over twenty and the exhaust is blue-ish.
i've read people getting the p1857 code after battery disconnect (which iT was before and during the recent work). i've also read that somehow a bad MAF sensor could be to blame and throws this code. can anyone confirm this? i just can't contribute the misfire to f'n up the timing job because wouldn't i get error codes related to timing? the only code that i'm getting is the
p1857 and the car does not run any different with the MAF sensor plugged in or out. I took it out and cleaned it and it's dated the year of the car 1998 a-6 2.8 qttr
any thoughts on my dilema?
thanks......