Ls1 running lean from mod's
 

I currently installed KN high flow lid, granatelli high flow mass air sensor, 80mm bbk throttle body, ppc long tube headers, random tech high flow cat's and american thunder flowmaster system. After installation I was getting a service engine code po171 and po174 which I believe is the fuel trim system running lean on bank one and bank two. The car seems to be running fine once it is warmed up but seems to be starving for fuel when starting cold. The service engine light has gone off when actually driving the car and then came back on. Can you give me advise on how to correct this problem. Do I have to do any more mods like fuel injectors or afc, fuel pump or fuel regulator.

It's definitely the intake mods you have done. The lids in themselves lean out the air/fuel ratio. That's why the stocker has those bulges on the sides. The addition of the throttle body and filter media are also aiding to the mix. You woudl really benefit from some dyno tuning, or you can richen up the A/F ratio. Come summer it will no be as bad, but you are a good candidate for some tuning. :burn:

say what?

the bulges are baffles, nothing with the maf readings. TB and filter, also have no effect on the air fuel either.


the MAF, yes, that will cause you to run lean. But not the filter, TB, or lid

Ryan.

The MAF would be the main culprit, especially that granatelli one, its programmed to run lean. Leaning the car out is how a ported MAF in general helps the car make more power, in the case of the granatelli that's why its programmed to lean the car out.

What are those codes exactly? What does the scanner/autotap say as an explanation for them?

need to retune your car or put the stock maf back on.

a MAF translator should be able to fatten the car back up to where you want it ok, give that at try..

what is a maf translator, be more specific.

It's a box that hooks up to your maf that allows you to adjust the signal going to the computer. Therefore you can richen or lean your car out as needs be.

Mike