CEL on kpro - P1259 & P0134

[urbanracer.com]

hi people,

having the above problem thats making me scratch my head.. i got CEL the other day so i decided to plug in my laptop in my kpro so i can find out what error codes im getting;

P1259 - Vtec System Malfunction (Oil Pressure Switch)
P0134 - Air/Fuel Ratio (A/F) Sensor (Sensor 1) No Activity

car drives fine, no funny sounds except when i pull up to a traffic light my idle goes down to 600-500rpm. Normally it sits at 700rpm (this is with OEM ecu).

2 things i noticed on kmanger. First, in the readiness codes i get;
O2 Sensor - Supported - Complete
O2 Snesor Heater - Supported - Complete

I'm a noob when it comes to engine management but i am assuming that this means that the o2 sensor is fine?

Second thing i noticed;
In the sensors tab in the o2 field it is stuck at 0.70 V and the O2C field is stuck at -1.8mA. the S02 (secondary o2 sensor) moves like normal.

I've changed the secondary o2 sensor before when it was stuck and kmanager was giving me the error "faulty secondary o2 sensor".

so i am assuming that the primary o2 sensor is bung but it doesnt say that in the error codes should i have this changed (costly) or troubleshoot the vtec solenoid? i've got defi oil pressure gauge and the oil pressure seems fine, only when i pull up to a traffic light the oil pressure drops with the idle.

oh one more thing.. the CAM angle sensor and CAMCMD field isnt moving either. coudl this be because of the vtec solenoid issue?

thanks in advance for any advice

urbanracer

[revolution]

Ur 02 sensor is most probably dead. When this happens the RPM's at idle drop as you have described. Are you running lean? How is fuel consumption?

[Sypherg]

I had similar problem, the CEL light comes on a few seconds after starting up the car then it remains on. The car drives fine, but i notice fuel consumption has increased, checked the code and got the P0134 warning. I ended up replacing the primary o2 sensor with brand new OEM Honda item (Part#: 36531-PRB-A01).
Fixed the problem since...not sure about the P1259 code your getting though, that might be something else.

Is the CEL light always on after startup or just intermittent?

[urbanracer.com]

thanks for the response guys. i dont know about the consumption as i havent driven the car much since i had the error. it pretty much goes on straight away now. i suspect its in the memory? lots of black smoke usually comes out, so i suspect im running rich or there is lots of carbon clogged in my exhaust cas i run a silencer 90% of the time.

thanks for the part number!! just what i was after!! saves me from calling up honda and getting it, gonna get it online now.

hopefully that will get rid of the p0134 error, i'm not so concerned about the vtec issue, i hardly push it these days.. but maybe thats the reason i couldnt pull from my mates s14 last week

[Sypherg]

If you can wait, I wouldnt buy from Honda since it will cost you something like $426. I ordered mine from a trader for $275. But it took about 3 weeks since had to order from Japan, but its still original Honda item.

Just make sure that replacing the primary o2 sensor will fix your problem or you may waste your money buying the part since they are pretty $$$ for a small thing. Btw this is the one that connects to the cat, takes 10min to install.

My mechanic told me he had a customer with a CEL problem regarding the sensor.. he purchased a 2nd hand o2 sensor, it didnt work, he then purchased a brand new sensor, still didnt work.. turned out to be something wrong with his ECU.

[urbanracer.com]

thanks for that.. hrmm.. i still get CEL on my OEM ecu and CEL on my kpro, unless there is somethign wrong with my wiring. I'm convinced its my primary o2 sensor as im not getting a reading and the A/F ratio is pretty static.

i researched on clubrsx and found out its cheaper getting from the US. oxygensensors.com. works out to about 250-265 depending on the exchange rate.

[TYPEaarh]

oooohh good luck mate, (no help from me)

[urbanracer.com]

oooohh good luck mate, (no help from me)

ur an engineer.. u should be able to fix it!!

just an update. thanks to erik and his kick ass knockless tuning and ultra quick doubleclicking skills managed to get rid of the CEL! my kpro gets an a/f ratio reading and primary o2 sensor reading now.

chuck in my oem ecu and take my silencer out of the buddyclub spec 3 exahust (to get rid of some carbon) and still no error.. so will drive around now.