I have a 92 preldue with swapped in h23, with turbo, 5-7psi. aem rail, 450cc injectors, s-afc. the car runs good till I start to hit boost than than engine light comes on, than the cars run good till aboput 4000 rpm, than I have a lot of black smoke, it sputters really bad. I just put on a new o2 sensor like two days ago. so I check the ecu for codes this is what I got. 37-map sensor 41-o2sensor 7-TB sensor 12-egr 23-knock sensor. anybody have any idea on this? thanks ray

 

well the black smoke is going to be unburnt fuel. Same thing my brother's car does if he tries to run into boost over the mountain between here and the track. is the S-AFC your "tuning system".. as in did you do the AFC hack crap?

 

yea my afc is the only tuning thing, what hack crap? I just spliced the afc to the ecu, and messed with it from tehre, nothing eles was done.

 

the hack is what stops the map sensor into seeing boost. your ecu was not meant for boost, so it goes into limp mode. you put the settings like-35 across the board to lower the signal, but the bigger injectors make up the needed fuel. you then drive out of boost to the dyno for tuning.

do a search, there are millions of theard explaing it in detail.

 

Well, since your getting the map sensor i'm guessing you don't have check valves or a missing link and your map is reading boost which it's not supposed to do. Which can cause it to go crazy with codes. Have you retarted your timing at all since the turbo if not then your getting the knock sensor because your damaging your motor.

 

no check valves. i haven't messed with timing, although I checked timning and the red mark was in the middle of the check marks