i was just driving earlier the all of the sudden my check engine went off.... i just check the code and it was trowing code 67..anybody know what causes this? im at work right now and im 45min away from home to get my honda repair book..i just wanna where the codes coming from just to get me a heads up to see if its safe to drive back home..thanks

 

67 Catalyst low efficiency. (same as P0420)

i Didnt know if you looked this up yet or not. As to how safe it is i dont know, i dont really know what this code means.
sorry i couldnt help more

 

Do you still have the stock catalytic converter? If so it might be deteriorated from the inside. An exhaust system leak can set off that code, as well as a faulty secondary oxygen sensor.

 

no i dont..i purchase a MEGAN racing high flow cat...but then i still have both o2 scensor intack..also, i just recently change my primary o2 scensor month ago...
is this safe for me to drive around for now thoo? im just curios..thanks

 

how long have u been riding with that highflow cat?

 

You'll be fine...02 sensors are no biggy, but you'll probably end up consuming more gas then needed...I've driven 90miles b4 in the rain w/ an axle that was about to break, if that makes you feel any better....lol

 

This code occurs when your catalytic convertor doesn't use enough of the remaining oxygen in the exhaust stream to 'clean up' the emissions. If the secondary O2 sensor picks up higher than acceptable levels of O2, it will assume that the catalytic convetor is not doing its job, which it probably isn't since you went to an aftermarket one. Running with the check engine light on will result in poor fuel efficiency as the ECU goes into default mode and tries to run the engine rich with retarded timing to keep things safe. I'd put the stock cat back on. It's not like you got any power from the aftermarket one anyways, right?

 

in which o2 does codes really come from? the primary one or the second one...

I JUST NOT SURE WHICH ONE IS WHICH..TROWING THAT 67 CODE...AND WAS WONDERING IF WHAT DOES SECONDARY O2 DOES? I MEAN WHAT DOES IT DO...IM PRETTY SURE THE PRIMARY 02 IS THE ONE THAT READS AIR/FUEL MANAGEMENT.... THANKZ

 

bump

 

The second O2 sensor sends that code. Its only job is to monitor the catalytic convertor's efficiency. And you're correct, the primary O2 is the one that the ecu uses in closed loop mode to determine fuel metering. It is possible that the secondary O2 sensor is failing but since you said you just changed your cat, I'd put my money down on that.

 

That looks like an Ebay special straight pipe. Honestly if you went with a better quality high flow cat (ex.Car-sound), you wouldn't be having this problem right now.

Yeah I'm also betting that the Megan cat is tripping the check engine light via the secondary oxygen sensor. This could cause a rich condition as already stated above.

 

yeah i think so to..finally i got it resolve today..i reset my ECU then the check engine light went out..but then im not sure if it goes back again...my plan is just get me an OBD1 harness and p72ObD1 ecu..that might help me eliminate this second o2 problem and prolly gain more performance....thanks for all the INFO guys...that really helps me a lot ..understanding this code 67..