Hey everyone, Im new around here and need some help. I have a 2000 gs 400 that I drive pretty hard on a daily basis. I purchased a k&n system for the car, and within a week got code p0171. I replaced the mas, o2's, injectors, fuel filter, all that stuff. I cannot make the code go away unless I put the stock air tract back on, which makes the light go off almost instantly!! any help out there? the car is considerably faster and does get better mileage with the k&n system. ps, its not mental h.p., I'm talking bout' the ability to drift the car through a corner compared to just going fast around it. Anyone else had this happen????

 

That code normally associates with running too lean. Which is weird because I've had the same intake and I never got any code. In fact this is the first time I've heard of such thing.

In any case, did you make sure the clamps/hose are on tight?

Also disconnect the battery for a little while if you haven't.

 

I really hope you do this off the streets.

and as GSteg said, check for leaks.

 

Of course I dont drive like that on public roads, fast some times but not endangering, my buddies and I go to a track a few hours away. Anyhoo, yes I checked all of the clamps, along with any other place that air could leak, still without any luck. Always lean bank 1. I did only replace the front two injectors .

 

makes sure u dont put the mass airflow in backward

 

if your running too lean maybe, probably not, your injectors are just covered in ****. u use injector cleaner very often?

 

lol drift. go watch Fast and the Furious a few more times you riceboi.

 

Eventhough unassociated I would check your spark plugs. It could be ironic that as soon as you changed your intake that this code popped due to failing plugs. Once I got this code and I went nuts trying to figure it out. I change all 4 O2 sensors (very important, if you don't know which one is bad change them all as you could have replaced the non-problematic ones). I also found that 2 of my spark plugs were very loose! I tightened them up and re-set the ECU (very important as GSteg mentioned) by disconnecting the negative battery terminal for AT LEAST 30 minutes or more.

GL!

 

I was using "drift" to explain the power difference, the ability to break the tires loose would have been a better example. I'm not using a 4000 lb car for drifting....jackass. hockey ! Is that even a pro sport anymore????

 

Ive done all that, new factory spec plugs, resetting the ecu,checked for leaks of all types,changed the battery{hoping it was a voltage issue**

 

McKrevice, have you ever even had your car sideways, or do ya gotta be careful with it cause your PARENTS are still making payments on it? I guaranty I can whip you around a road course with my girlfriends lil' red vw bug. no drift. Are there sh-- talkers like you on every forum?

 

You know that little thing that connects to the back fo the stock airbox, it has two screws holding it, take a look at the stock box, I have a feeling you didn't take it off. that needs to stay connected to the stock vac line- and a new vac line needs to run to your new intake. Check that. You are deffinatelly sucking unmetered air somewhere.

And yes, there is always someone to say something stupid. Not everyone is like that. Welcome to the forum.

 

Its the MAF sensor clean it, if you still get a CEL after then buy a new one.

 

He said he replaced it.

 

Oh sry didn't see. Just read p 0171 and remember that i replaced mine and it got fixed.