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Q: Codes P1166 & P1167 on 2004 Hyundai Sonata

If certain codes do not exist, then why is it reading them? I have a P1166 & P1167. I am told these do not exist but yet others say it is the O2 sensor...
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The codes P1166 and P1167 have to do with the Computer System adapting the Fuel Mixture to a compensation set point and when it can't go any farther, the Computer sets a code P1166 when the system is still too Rich and or a code P1167 when it is too Lean.
Here are 2 articles about these codes in the more common code format i.e P0171 and P0172 I wrote these articles because many shops are stumped with these problems and I do Emissions work in CA and have to solve these problems every day, so I have spent a lot of time on them.

read these complete articles, even though it may seem really boring, these code conditions still throw more shops than any other codes. Then take your car to a good shop that can read and understand these articles and do a proper Diagnosis, by following the Inspections in these articles. Don't rule out a defective Mass Air Flow Sensor and if so, ONLY use a factory replacement part, as this part is a critically precise component and the after market sensors have lots of problems.

I have a 2000 Hyundai Sonata 2.5L, took it to Hyundai Service Dept. because of surging prolbems when you let off the gas??? Since it has been at their dealership they have told me they had pulled two codes from the computer (P1166 and P1167). I have my own code scaner! When I took the car to them it had no check engine lights on. Now they are not saying any thing about O2 Sensors or MAF (air flow sensors)he said he didn't know
what one of the codes where? Wasn't in his book??? Now they are telling me the car won't run and it needs a
new Fuse Box, if you can beleive that??? I have read some of the recall list for this car and the O2 sensors
are a big problem and it also had MAF sensors on the list. What to do with this problem with this dealership??
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