getting a CEL after my EVO and FMIC install

[red_devil]

I continue to get 2 codes show up on my check engine light.

First is knock sensor malfunction. This came on every so often when my car was stock. Now it comes on right after I remove the CEL. I replaced the knock sensor last year. The car itself is running better than ever, smooth idle and smooth accleration.

Second code is fuel trim malfunction bank 1. Which I really dont know what that means.

Like I said the car is running great, so should I just ignore the CEL light and maybe just remove the bulb?

Any ideas?

 

[spyderturbo007]

Second code is fuel trim malfunction bank 1. Which I really dont know what that means.

During light cruise / idle conditions, the ECU determines fuel delivery based on O2 sensor feedback. If it sees a lean condition (AFR >14.7:1) it will increase fuel delivery by increasing the STFT (Short Term Fuel Trim). If the O2 sensor returns a rich value (AFR <14.7:1) the ECU will decrease the STFT, thereby adding less fuel during the next cycle. If, for example, the lean condition persists, the STFT value will be transferred to the LTFT (Long Term Fuel Trim) and the ECU will return the STFT to 0.

The problem is that the ECU only has a limited adjustment range to deal with lean, or rich conditions. If I remember correctly, for the 2g, it is + or - 17%. When it reaches this limit, it throws the P0170 CEL. Normally the problem is a dead, or dying O2 sensor.

Did you remember to plug the O2 sensor back in after the 16g installation? Is it possible you damaged it when you did the installation? Do you have access to a logger?

Like I said the car is running great, so should I just ignore the CEL light and maybe just remove the bulb?

Any ideas?

Fuel trims only apply at light cruise or idle, so the car will be no different at WOT. Pulling the bulb for the CEL doesn't fix the problem, it just covers it up.

 

[FORMONTOYA]

^^^Good explanation of the P0170 code and also the main culprit behind it. Also your "state of tune" will be another reason why you get this code.

Is the knock sensor torqued down properly? Too lose or tight will effect its operation.

Removing the CEL bulb is not a good thing to do. What happens when you get another code? You won't know, will you?

 

[red_devil]

I did clean off the o2 sensor when I reinstalled it and it is plugged in. I pulled the plugs today and they are black so I'm running rich for sure. Im also getting around 18mpg so could my 02 be dead?

I dont have a logger right now, and I understand that my semi mods can make things like this happen, but im running 13psi at most with a slight boost leak somewhere so why is it still having a cel?

I do have access to a series II decoder so I can always get readings on my car.

 

[RedTurboEclipse]

The P0170 code for fuel malfunction.. just curious, is your BOV recirculated?

A long time ago when I actually had a Red Turbo Eclipse, aka my first DSM, I was running vented and would get a CE light, and always wondered why, and it only happened when I was venting. If I can recall that was the CE code.

 

[red_devil]

no I have always ran recirculated