Just do a double check on your battery ground. Bad grounds can cause all sorts of headaches, poor sensor performance, and more importantly, bad ignition performance.

unbolt, clean, re attach. simple 5 minute job

 

More like a 30min job once you have re-set your clock and radio stations.
It seems Honda chose a painted part of the chassis to run the earth cable to so the only metal to metal contact is via the machine screws thread and not the terminal plate. Sanded it all up to fix that including both sides of the terminal plate and both sides of the fasteners washer. Contact cleaner to prep, re-assemble and then soft-seal for a bit of corrosion resistance. Didn't notice anything and cranking voltage is identical but no harm.

 

I use silver anti-seize for corrosion protection. it has a good habit of being cheap, the containers come with the brush attached to the bottom of the cap, and you can get good clean coverage without the goopy mess of grease

I recently installed a ultracapacitor and did this to all connections.

Longterm connections, and stupid fast starting!

 

hi there have taken out 1300DSI motor out of 2006 honda fit n replaced it with 1500 vtec swaped the loom n ecu everything work but 1300 had 2 O2 sensors, the 1 past the cats connected but theres not 1 on the top of exhaust like on the 1300,did a scan n engine lights on coming up with the code P0135 which is telling me O2 SENSOR.It runs fine just want the engine light out,theres a plug on the trans for were a sensor is suppose to plug in but no sign of a O2 SENSOR ANY WERE.HELP