A/F Sensor Slow Response

SWEliseK20A · Post by **SWEliseK20A** » Wed Sep 23, 2009 6:09 am

Hi there,

K20A2 engine from UK Civic Type R, fitted with JRSC.

I have just fitted a High Flow sports cat so that I can get my car through the emissions test (will be taken off again after the test). Prior to fitting the cat I was getting Zero error codes, since fitting the cat I now get 1 error code, A/F sensor slow to respond. I am only running the primary 02 sensor which is located just before the cat. I am just wondering if the fitting of this cat is whats causing the error code, will the lambda sensor be picking up some ‘swirl’ prior to the cat, obviously it’ll not be flowing as freely as it was with No cat. Its a PRB Ecu with the genuine Honda 4-wire ‘wideband’ lambda. The sensor is also brand new so I’m pretty sure its not that thats bust.

Can anyone offer any advice please.

Thanks in advance,

Scott

Post by **Spunkster** » Wed Sep 23, 2009 9:21 am

It is possible that the O2 sensor was damaged when installing the cat. THey are very sensitive to vibration.

SWEliseK20A · Post by **SWEliseK20A** » Wed Sep 23, 2009 10:14 am

Thanks,

Is there any way that I can check it for damage, can I meter across the pins and look for readings within a specified range? The cat was offered up to the car and marked etc then taken off again prior to welding, then re-fitted once welding complete. There wasnt any banging or any other work which would have caused serious vibration, infact any vibration would have been less than what the sensor would experience on the road in general day to day travel.

Post by **Spunkster** » Wed Sep 23, 2009 11:49 am

What vehicle is this in?

SWEliseK20A · Post by **SWEliseK20A** » Wed Sep 23, 2009 1:24 pm

Its a K20A2 motor fitted in a Lotus Elise. The K20A2 is fitted in the UK Type R, same motor as your RSX Type-S I think.

It is fitted with a JRSC with a 3.4" pulley, PRB ECU with Hondata K-Pro Serial No 4822 and Honda Wideband Lambda, Honda Part No: 36531-PRB-A01 (2xBlack wires, 1xGreen wire and 1xWhite wire)

Engine Loom is completely standard and unmodified, wiring Mod for PRB ECU has been carried out. Connector E Pin 4 (PNK SG3 Sensor ground) is looped to Pin 16 on the A connector (this pin is unused on the UK Civic Type R). This mod is obviously to ground the Sensor. Connector A pin 22 (again unused on the UK civic type R) has been provided with a switched live.