Running really lean and would explain the stalling.

P1166 Hyundai - O2 Sensor System Lambda Controller at the Limit Bank 1

Possible causes
- Air leakage or restriction in intake or exhaust system
- Dirty engine oil or oil level too high
- Front HO2S or MAFS contamination
- Fuel system
- EVAP system
- Faulty sensor signals

- Engine Light ON (or Service Engine Soon Warning Light)

P1166 Hyundai Description

The Lambda closed-loop control system is included in the engine's control system. The control system regulates the lambda upstream with the HO2S signal. Rich mixtures generate high concentrations of CO, H2, and HC. Lean mixtures generate the high concentrations of NOx, and free oxygen.

If the lambda controller reaches the maximum or minimum threshold, then feedback control is no longer possible and emissions will be increased. The ECM sets DTC P1166 if no proportional fuel adaptation occurs for a defined time after the lambda controller has reached its minimum or maximum threshold.

Read more: P1166 Hyundai O2 Sensor System Lambda Controller at the Limit Bank 1 OBDII Engine Light Trouble Code | Engine-Codes.com
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Yeah thats what I was thinking too. I just dont know where the cut off of air is occuring. I took the air box and out and the battery to look under to see if any acorns were in there (I'm set on the acorns, or damage caused from the acorns.)


I'm convinced theres either a leakage of blockage somewhere. Could it be as simple as a MAF? or what about an air intake control valve?

 

It could be a dirty MAF.

 

The first step to diagnosing your problem is identifying which adaption limit the PCM has reached. Has it been reacting to an O2 sensor lean signal by adding fuel or reacting to a rich signal and taking fuel away. There would be no point searching for a vacuum leak/exhaust leak if the PCM has been removing fuel from the mixture, for example.

I don't think your problem will be a dirty MAF sensor, for two reasons...1st, because you say the engine is stalling which makes me think the PCM is removing a lot of fuel from the mixture. That's the opposite of what would happen with a dirty MAF...2nd, because your engine probably doesn't have a MAF sensor. The 2.0 engine (the ones we have here in the UK, at least) have MAP sensors.

Regards.

Scottie.