2G Check Engine Light is on

[szl98gst]

Had check engine light on today, i went to auto zone they did a diagnose and the code come out to be fuel trim mal functional, which the guy works at auto zone said had never seem one like it before. Also, the car has realllllllllllllly bad gas mileage, about 15m/g on highway, and the mods i have on the car are only BoV, Intake, and 3inch exhaust all the way. Any help will be greatly appreciated!

 

[SpeedFreak03]

http://www.dsmtuners.com/forums/showthread.php?t=116422

^^Check out this thread. Seems to be a common issue. But first try cleaning (with the electrical contact spray cleaner stuff) the connectors on the injector wires, maybe they aren't making a good connection with the injectors. After resetting the ECU (unplug battery for 15 minutes, let idle for 10 minutes) it still throws a code, could be an O2 sensor. From reading the thread above, seems like replacing the front O2 sensor solved the problem for some, but other people had different solutions.

 

[szl98gst]

Hey guys! I posted this earlier but no one had an answer for me, so im relisting it. The car's having the light on for the past few weeks, i tried to clear out the code by disconecting the battery on and off and it erased code for only couple days then it came back on. Please, any suggestions??

 

[justin0469]

if its p0170 its because your fuel trims are so out of whack the ECU doesnt even know what to do. can be from having bigger injectors and other fuel system upgrades without a way to control them or not controlling them properly.

 

[turbolover2]

What was the code? That's the first and only place to start with this problem.

 

[szl98gst]

fuel- trim mal-function #1, thats it shows up on the logger.

 

[knighteclipse1]

It could be many things, anything from a bad MAS or a bad O2 sensor, when mine had this problem, it was just after I had installed a 3 inch turbo back exhaust. It ended up being the upstream O2 sensor. Problem fixed.

 

[szl98gst]

Just change the o2 sensor today, and had shop to clear the code. I prayed the light wont come on, but unfortunately it came on after i drove the car around 10 miles. Getting really frustrated on the car. Any ideas?? For such P0170 code, what else could be wrong besides o2? I'm willing to do a complete replacement. Also, car runs at really bad mileage as stated above and the rear bumper wears a black coat all the time. Help please!

 

[PoorDSMowner]

I am going through the same problem. I have P0170 running as well, and it threw right after I put in a 3" cat-back. But I have a screwy 1st cylinder plug wire. I havent went to replacing things, but you are not alone. I have a nice coat of soot on my bumper and am getting TERRIBLE mpg. 13.7 the other day :-(

My mods include Intake and Exhaust. Nothing nearly major, I was hoping it was my plug wire not firing well

 

[szl98gst]

Incorrect installation of the spark plugs can cause the ecu to throw a code??

 

[allgripnoslip]

blah mines doing the same thing and all i have is an injen intake, mbc 1g bov and 3" turbo back. happened after installation of my turbo back. My rear O2 is rewired to simulate normal reading and i am getting the P0170 code.

Also i pulled my plugs and they are super black, i just cleaned them up with some sand paper but i want to know why the fuel trims are so messed up