My CEL light has come on, and I checked the code using the paperclip method and got 45.

I think this means Fuel system too rich or lean.

Looking for advice on how to troubleshoot this one, I am not sure where to start. I do notice that since the code came on, it seems to idle very low when in park.

Michael

 

Since it's a 2005, you'll get better information by going to someplace like AutoZone for them to use an OBD-2 code reader.

Code 45 by the paperclip method can be any of several codes by OBD-2.

Meantime, check your oxygen sensors. They actually measure oxygen DIFFERENCE between inside & outside, so look for exhaust leaks blowing onto the outside of the sensor. Or oily crud dripping onto the sensor. Stuff like that.

 

I went to Autozone and they put the code tool on it and it came up as
P0171 45 System Too Lean

They mentioned checking for an air leak somewhere?

 

Most likely reason is an air leak. Check all vacuum lines, PCV lines, intake duct, clean/check PCV valve, Evap cannister, intake manifold, brake booster hose. You can use throttle body cleaner or propane (safer) sprayed on potential leak sites to check for idle changes w/ engine running. A smoke generator can be used to inject smoke into intake duct and detect intake leaks w/ engine off. I used a cigar taped to a air siphon tee to generate smoke.

There are about numerous additional reasons for this code; exhaust leak ahead of primary Air/Fuel sensor, low fuel pressure, ECT sensor, MAF sensor. If you plan to DIY, suggest purchasing a Honda shop manual. You can get an emanual from ebay seller automanualsource for $21.99.

good luck