My car is runnig around 14.5 AFR on 0% column.. And my car's MPG is still really horrible.. I am getting about 10 MPG.. Is my o2 sensor bad? I had P2A03 A/F Sensor Circuit (Bank 2, Sensor 1) Circuit Range/Performance one time.. Is my stock sensor bad?? Please help..!!!!

 

Oh.. And my exhaust gets really black after few min of driving car.. Am I burning too much oil?? My oil dropped to half down from the H mark. I have 300 miles to 3000 since I put oil.. It never done this before.. And it suddenly started.. Even when I set my car to little leaner I still see black exhaust.. Something wrong??

 

Are you N/A? Can you drive around in MAP 0 (stock mode) and does the situation improve? How are you reading AFR and can you read both banks to compare?

 

Where are you reading the a/f from? How are you calculating MPG? What all mods are done to the car?

More specific questions/problems will result in better answers.

 

I have HKS Exhaust Z-Tube, MD Spacer, and MREV+.. I'm calculating MPG by how many miles I drove divided by how many gallons I put in whenever I fill my gas up..

Oh.. I'm reading AFR on Passenger side of the pipe with Innovate LC-1..

 

What is your A/F in other areas of the map? Running a 14.5A/F at idle shouldn't effect your MPG.

 

if anything ur mpg should stay about the same, maybe even go up because ur making the engine breathe better. almost sounds like ur running too rich. do you have test pipes on? because if u hav cats there shouldnt b black on your bumper.

 

Do you have any codes now? Does the car drive well?

 

No.. I don't have test pipe.. and I am keep getting P0300 which is missfiring.. I grounded my UTEC really good with ECU and evrything.. But it seemswont go away.. And now its throwing P0051 which is something about Bank 2 Sensor 1 heat sensor or something.. And P1168 which I don't really understand.. car drives really bad.. but as soon as I WOT car seems like its running fine.. Should I set my parameter on UTEC to run on closedloop? cause I have it on openloop.. is my O2 sensor bad?? hopefully its just something really simple.. I was looking at the Infiniti service manual for the code I got.. And they were saying something about Cam positioning sensor.. where is that at? And my MPG goes back to 13 to 17 if I take UTEC off of my car.. Thanks for help guys..

 

It sounds like your stock ECU is possibly in 'limp' mode and batch firing. You need to figure out what is causing the codes, get them cleared, and then start over. I would probably remove the UTEC from the car for the testing.

Batch firing will KILL your MPG, as you are injecting fuel in to every cylinder, every cycle.

The cam sensors are located on the cams, toward the front I believe.

You may have a bad fuel injector output on the UTEC that is causing the misfire, you could check that with either an o'scope or a frequency meter. You would want to test each one and make sure they are roughly the same frequency at idle. You could do the same for the coil packs, as the UTEC may have a bad coil output.

 

Crap.. I don't have osiloscope to check the frequency.. Dang.. I checked the voltage of of the injectors on UTEC.. And they were around 13.5v DC at idle.. And it goes down to 7 v as i get to 5k rpm.. But I guess I looking at wrong thing.. Oh and the voltage coming out of the ECUs injector ports are around 9.5v.. I don't know if that helps any.. Is there any other way to check them?? and what do I go if I find out they are sending different output.. THanks..

 

Does your car have thick smoke coming out of one side at idle? Can you smell the excess fuel? Call turboxs and get that UTEC swapped out if the problem goes away when you switch back to your stock ECU - their phone support is outstanding. All of your problems appear related to Bank 2, which is driver's side I believe. That's the same side that my 1st UTEC failed on as well.

 

You're fuel injectors shouldn't read 13.5 at idle. They should read much lower then that. They are 12vdc injectors that are running at a very low duty cycle (PWM). If they are reading a constant 13.5 volts they are dumping fuel. I would guess, as RCDash says, you will see black smoke and all that.

 

Should I just try to hook it right into the ECU injectors wires??

 

Yeah.. I called them.. And they weren't really helpful.. The guy said he doesn't know what to do..

 

what? have them RMA it if operation returns to normal when you go back to stock... what's to figure out?

 

Ok.. Now I don't know what happened.. But suddenly.. My exhausts are shooting think white smoke out with or w/o UTEC.. I don't know what I did.. Are my injectos bad now?

 

Make sure your stock ECU is properly grounded.