i have been posting threads and not really ending up much farther with my problem. i have a 2004 g35 with 100,000 miles. i have intake , spacer, and jic 3inch midpipe straight back. the check engine light is on. code P0171. fuel injections system too lean- bank1 (cylinder numbe 1 denotes bank 1). PROBLEM CAUSE.. low fuel pressure or restricted flow.. ignition system fault..large vacuum leak...faulty maf.. i clean the maf. also tried resetting the battery and nothing. the car i feel should run a lot better to. a guy at the tune shop said o2 secondary sensor simulator would take care of the problem and it was $75.00 and what exactlly is that process about? i will prob have him do that but any other suggestions of the problem i have and anything cheap to get the car running alittle better. how would i go with getting a tune ? or would reflashing my ecu help me out with this. if so any suggestions on a place.

 

more likely to be the afm......or intake leak

 

So you still have your cats? If not, you may be getting a fouling on the second O2 sensor. What did you use to "clean" the MAF sensor? How did you "reset" the battery (ECU)?

 

yes i do have my cats still. i used electic parts cleaner to clean the MAF and i unplugged the negative cable for awhile.

 

just because you clean it doesn't mean it will fix it if it's faulty......i've replaced AFMs that were acting up and didnt throw any codes....

 

Sounds like the MAF. Thats a very delicate piece to try and clean. I'd replace that and then do a proper ECU reset.

 

As said above, MAF sensor is very delecate. You should use ONLY MAF cleaner for the job. A lot of "electroncics" cleaners "degreasers" will eat plastic parts.

 

thanks i dont understand what the problem is with the MAF .. i understand its not working properly but what is with the part to actually have my problems occur? shouldnt i be getting some bucking and not going over a certain RMP, or is just not doing its full job sending a code? what is the proper way to reset the ECU?