Air fuel ratio really rich (2018 Mustang gt)

[maxcraig00]

Hey guys quick question.(2018 mustang Gt JLT CAI, E85 tune). I have been getting code p0003 on my lund tuner. It says heater control circuit. My air fuel ratio is super rich. 8.5-9.8 on idle and doesnt change on WOT. Sometimes it jumps to 10.5. I am currently on E85 and it been on E85 for the past 6 months. I tried cleaning my MAF sensor. I dont know what the problem is. But it seems I am running to rich.

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[blackyote_317]

Hey guys quick question.(2018 mustang Gt JLT CAI, E85 tune). I have been getting code p0003 on my lund tuner. It says heater control circuit. My air fuel ratio is super rich. 8.5-9.8 on idle and doesnt change on WOT. Sometimes it jumps to 10.5. I am currently on E85 and it been on E85 for the past 6 months. I tried cleaning my MAF sensor. I dont know what the problem is. But it seems I am running to rich.

I'm not on e85 but I'm pretty sure that's exactly where your AFR should be...I don't think that has anything to do with your code.

 

[SheepDog]

Your AFR is about right for E85. Just depends on the actual alcohol content. Perfect Stoichiometric ratio for E85 is 9.8:1

 

[SheepDog]

Also, code P0003 is a generic OBD2 code for Fuel Volume Regulator Control Circuit Low. It has to to with your high pressure direct injection system. Check the fuel rail pressure sensor, connector and wiring

 

[3star2nr]

Hey guys quick question.(2018 mustang Gt JLT CAI, E85 tune). I have been getting code p0003 on my lund tuner. It says heater control circuit. My air fuel ratio is super rich. 8.5-9.8 on idle and doesnt change on WOT. Sometimes it jumps to 10.5. I am currently on E85 and it been on E85 for the past 6 months. I tried cleaning my MAF sensor. I dont know what the problem is. But it seems I am running to rich.

Check for vacuum leaks down stream of the mass sensor.
Check for bad o2 sensor.
Contact lund, send data log

 

[EFI]

Your AFR is right, E85 requires quite a different ratio than E10.

 

[SheepDog]

Check for vacuum leaks down stream of the mass sensor.
Check for bad o2 sensor.
Contact lund, send data log

Vacuum leaks cause a lean condition, not a rich condition.

 

[EFI]

Vacuum leaks cause a lean condition, not a rich condition.

Which none of those are present in the OP's post, so not sure why he's having him go on a wild goose chase for a phantom problem.

 

[SheepDog]

Which none of those are present in the OP's post, so not sure why he's having him go on a wild goose chase for a phantom problem.

Truth. The moral of this story is that there is no problem. OP's AFR is correct for E85.

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