Are you using EAT chip? This can really affect it. High HC means too rich of fuel mixture... maybe your air flow meter is not that great...
hey guys, finally passed the car. the new 2.0" dual hi flow converters and cat-back exhaust did the trick... my NX dropped A LOT... saying to me that my cats were all gunked up. I also replaced the O2 sensor, which was not all that old to begin with, but what the hell.
However, i just barely passed on HC... 272... he said limit is 275....what gives? High mileage? New plugs? I changed my oil the night before inspection. Plugs could be fouled, they might be old... like 20k. What else should I check? Any input is appreciated.
Are you using EAT chip? This can really affect it. High HC means too rich of fuel mixture... maybe your air flow meter is not that great...
How long has it been since the battery was unplugged? The ECU will have to relearn the fuel trim map to get to the proper mixture for emissions. If you cleared the learned map or replaced the O2 within the last 50 miles or so, it may still be settling in.
Robin
72 Chevy K10
01 E39 M5
Originally Posted by Robin-535im
No EAT chip...
battery has been off about 50x in the last month... i do a lot of work on the car, also replaced the O2 on saturday of last week