would a faulty tgv controller on manifold cause a P0171 lean mixture fault???? car is 01 wrx bugeye.

 

It could be various things mate , tgv , manifold leaks , icv , maf ,
It's gonna be a case of going round everything , cleaning bits , and making sure everything is tight

 

thanks, ya ive tried alot of things already,new gaskets everywhere haha,tried new maf, new 02 sensor. ive narrowed it down to a tgv controller as i had it on rolling road early this year and guy said one controller didnt seem to be working.he never got to do much more cause engine started knocking. rebuilt it and 4k later it knocked again.fitted 2nd hand engine last weekend so need to get this lean fault sorted asap

 

How about Delete the tgvs and get it mapped ?

 

ya true,will be geting it mapped when i can save some money,but just want to get rid of this engine light so it safe to drive. at the mo im driving it slower than a ride on lawnmower