chris_barry

I've used these guys several times for K20A o2 sensors. They seem to use name brand sensors which come with right plugs ready to plug in place of OEM units.

http://www.oxygensensors.com/

YLDS2K

Can a faulty O2 sensor be damaging to fuel economy...if so which sensor?

chris_barry

A bad primary will result in the ECU not running closed loop and going to the base map. The base tables are richer and therefore economy will suffer.

YLDS2K

What's the best way to identify a faulty O2 sensor?

AusS2000

If your O2 sensor is dud don't you get a check engine light? And then pull codes and get Code #61. Hey presto.

YLDS2K

Nah I don't have a check engine light come on yet although am just noticing a down turn in fuel economy

AusS2000

I wouldn't jump to the conclusion it's the O2 sensor. Could be one of a hundred things. Could even be you're just driving harder.

chris_barry

Bolt on an air fuel meter and check the car is running at 1.0 lambda on idle, light load and cruising. If so the O2 sensor feedback is working fine.

YLDS2K

Well that's the thing my driving habits have changed and less frequently engage into vtec. But maybe a combination with exhaust/HFC/CAI it might of thrown it out a little.

I think I might need a piggyback ecu to have everything running right

triccytriddy

i didnt get a check engine light, i jus got bored so pulled the codes & 61 jus happened 2 be sitting there waiting. i'll soon fix that