I always get the check engine light when I WOT in a low rpm with the FCON tuning. When I clear the code it reads bank 1 running rich. The question is can I put a check engine eliminator between my exhaust and o2 sensor? I am talking about the extension o2 bung found on the internet.

 

I get the code now and again. It means nothing as the 02 sensors are not used for fueling. You could completely remove the sensor and it would have no affect. that said, I don't think a nonfouler would have any impact on getting rid of the light.

 

+1. I have the non-foulers and still get that code. My light is almost always on. I don't even bother clearing it anymore. It's weird though cause sometimes I'll start the car and have no SES.

 

Since the factory Ecu has no control over fuel and timing ,it keeps trying to make corrections to the fuel trim and when it does not see the desired changes according to its correction its flagged the service engine soon light accordingly, I had managed to make the Ecu stay in open loop at idle and build a fuel map very close to what the factory Ecu like to see in vacuum witch made the car drivability and idle beyond perfect and the service engine soon light did not come on for weeks, but not permanently. steel trying .

 

Mine comes on also but stay on. Sharif will clear it and it will be good for a week and then it comes back on??

 

mine comes and goes, i have an 03. I assume the factory wideband cars have it much worse then mine.

if there is enough demand for a solution, i have a friend who builds calibrated primary O2 eliminators that are intended for precisely this situation. he developed them for turbo vipers we were building at work since we would keep the stock ECU in with the Motec just like this with the FCON.

i can get us sims that would emulate all 4 o2 sensors under perfect conditions. how successful this technique would be, depends on how intelligent the ECUs circuit detection is... specifically during cold start and stuff when it might find it wierd to get a perfectly clean o2 reading. but its worked fine in other cars so it should be good.

 

Yup, Sam is correct. Trying to keep that CEL from coming on is super tricky. Even the slightest changes in AF ratio at idle, part throttle, and cruise, can cause the CEL to come on...as the ECU is trying to correct fuel...but has no control over fuel. Since the stock ECU has no control over fuel trims, it's darn near impossible to prevent that light from coming on.

Regardless, the cars run great, and I just ignore the CEL.

 

Does UTEC not have this problem because the ECU controls at startup and idle?

 

The reason why the uteck does not have this problem ,because it oprates as a piggyback in closed loop and act like a standalone in open loop operations,witch the factory Ecu is not looking at the fuel trim any more at that stage .

 

Thank you.

 

when mine does it, i just retune the car, it goes off once a year when the seasons change. All we did was some datalogging, and did a street tune

 

If your friend is able to makes one that works, please put me on the list.

 

That would be awesome. I hate having that stupid light on and am worried that I would miss a real issue because I think it's the rich code...

On top of it it's embarrsing when you're trying to show off your car and there's a check engine light running...doesn't matter how fast the car goes first reaction is always: Dude, why do you have a cel? anything wrong with the car?

 

Since the FCON controls the A/F ratio do I still need the maf sensor? I don't know much about tuning but I have seen photos on the net of Z's with the FCON and it looks like no MAF sensor.

 

you can take out the MAF. the FCON has a voltage output that is used to emulate its existence to keep the stock ECU happy. So even if its still in there, its not even doing anything, its signals have been completely bypassed.

 

I had planned on just covering up the CEL with some tape.

 

I think the ultemate solution is going to be the flash program form cobb ,witch will allow you to turn off any check engine light permanently ,this is going to be the only solution as it has been proven in the Subaru platform

 

you have a pm.

 

Does this also keep the code from being stored in the ECU so that people can pass emissions diagnostic tests?

 

I run the Cobb system in my Subi, and once you turn off the code, the ECU just ignores any errors... It doesn't trigger the check engine light or flag any codes... I've had my dealer run their scan tool and nothing shows up...