leaky brake booster

[eric27]

i have a couple questions about the brake booster and the maf. i pulled codes and get a 118 and 412. also sometimes seeing the 159 and the 998 hard fault code.y first question is what affects will be caused by my leaky brake booster? it is leaking inbetween,beneath the studs.

my truck runs okay without my maf connected. but seconds after plugged in it putters and i have erratic rpms....unplugged i get 11mpg plugged in its about 9mpg. i havew e replaced the maf. one o2. cleaned the iac and swapped to check for a difference. new fuel lines, pump and filter. new airfilter. etc. could it just be the other o2. or could my hissing brake booster be setting off codes and messing with my idle. thaks to all who reply

 

[IZwack]

A leak in the brake booster (hiss) is pretty much like having a hole in the intake plenum - it is introducing "unmeasured" air volume that is bypassing the MAF. So definitely replace the booster before you try anytihng else like replacing an O2 sensor.

 

[eric27]

thanks i wasnt sure. it has been aggravating ......thats for sure.i booought the 93 for 1000 dollars and put 1299 in it so far. still runs like crap. had the brake booster hiss since i got it. after swaping for new or clean parts it seemed to run good for about a week then problems started again. ill fix the leak and get back with ya for the results....thanks again... guess i cant complain too much with 350000 miles on it!!! :biggthump