CEL P0170 Fuel Trim Malfunction

This cell popped up the other night when I was just normall driving. I had ran it hard earlier that night but, at the moment it came on I was daily driving. This cell came up once before. I would just like to know if anyone call tell me some details on this cell. It reads P0170 - Fuel Trim Malfunction (Bank 1)

Fuel trim is maxed out in one direction or the other, and the ECU still wants to adjust it further.

Ah thanks. Is this probably due to the 650 injectors and using the afc to tune?

What are your low settings on the AFC?

The low throttle is set at -30% up till 3k then it goes to -31%

My car just threw the same code. I've been trying to figure out what it means. I have 450cc injectors set to 32psi at idle. Runs rich as crap but its the best I can do until I get a piggy back. So I guess what this code is telling me is that the ECU isn't capable of leaning out the mixture far enough? Is this right?

You're fuel psressure is 32 psi? If so, the ECU is not trying to lean out, but add fuel ;)

The AFC settings above seem right on, so no smoking gun there.

You're fuel psressure is 32 psi? If so, the ECU is not trying to lean out, but add fuel ;)



But my car is non turbo.....wow, this is confusing.

Shit, I have no idea what a NT FP should be. Still seems it would need to be higher. Injectors are rated at 43 psi typically, and manufactures usually stay within 5 psi or so.

Shit, I have no idea what a NT FP should be. Still seems it would need to be higher. Injectors are rated at 43 psi typically, and manufactures usually stay within 5 psi or so.

Well, see the car came with 275cc and I swapped them for 450cc in preparation for turbo. 32psi was as low as I could get my FP. The car is obviously running pretty rich which I guess is due to the over sized injectors and not having the compensating airflow from the yet to be installed turbo system. So my guess at why I was getting the code is that I figure the ECU has leaned the system out as far as it can which still isn't enough. Does that makes sense? lol. I need to hurry up and get my piggy back and finish getting all my turbo parts so I can install them and get this beast running right.

That does make more sense. :) Can't expect to run the "wrong" injectors and not get a fuel trim CEL! :D

Just for fun, because I'm a sick, sick man, and this is fun for me, you would need to lower fuel pressure to 16 psi to make 450s flow like 275s. :D

Edit> More fun... At 32 psi your injectors flow like 388s. They are still 30% too big. The ECU does not have that much range. A 2g turbo ECU (not sure about NT) can adjust LTFTs up to 12.5%, and STFT up to either 12 or 16%. Not enough to cover a 30% discrepancy. So the CEL certainly makes sense.

See, isn't this fun?

Wow. Your just too good.

Lol yes he is. Oh, and I have popped this cell 2 more times since I have posted this. Infact my car sits in my driveway with this code again. It seems to come on when I am daily driving which is wierd too. Not like I'm at WOT on the interstate running from the cops when this thing comes on. Probably like under 40mph and like 30% or so throttle. I'm not too worried about this issue because, I am almost positive it is running too rich. I'd rather be rich than lean untill I get dsmlink.